NAME | SYNOPSIS | DESCRIPTION | GETTING STARTED | TROFF IDIOSYNCRASIES | A MANUAL PAGE TEMPLATE | CONVENTIONS | TITLE MACROS | INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS | MANUAL DOMAIN | GENERAL TEXT DOMAIN | PAGE STRUCTURE DOMAIN | MISCELLANEOUS MACROS | PREDEFINED STRINGS | DIAGNOSTICS | FORMATTING WITH GROFF, TROFF, AND NROFF | FILES | SEE ALSO | BUGS | COLOPHON

GROFF_MDOC(7)       BSD Miscellaneous Information Manual       GROFF_MDOC(7)

NAME         top

     groff_mdoc — reference for groff's mdoc implementation

SYNOPSIS         top

     groff -mdoc file ...

DESCRIPTION         top

     A complete reference for writing UNIX manual pages with the -mdoc macro
     package; a content-based and domain-based formatting package for GNU
     troff(1).  Its predecessor, the -man(7) package, addressed page layout
     leaving the manipulation of fonts and other typesetting details to the
     individual author.  In -mdoc, page layout macros make up the page
     structure domain which consists of macros for titles, section headers,
     displays and lists – essentially items which affect the physical posi‐
     tion of text on a formatted page.  In addition to the page structure
     domain, there are two more domains, the manual domain and the general
     text domain.  The general text domain is defined as macros which per‐
     form tasks such as quoting or emphasizing pieces of text.  The manual
     domain is defined as macros that are a subset of the day to day infor‐
     mal language used to describe commands, routines and related UNIX
     files.  Macros in the manual domain handle command names, command line
     arguments and options, function names, function parameters, pathnames,
     variables, cross references to other manual pages, and so on.  These
     domain items have value for both the author and the future user of the
     manual page.  Hopefully, the consistency gained across the manual set
     will provide easier translation to future documentation tools.

     Throughout the UNIX manual pages, a manual entry is simply referred to
     as a man page, regardless of actual length and without sexist inten‐
     tion.

GETTING STARTED         top

     The material presented in the remainder of this document is outlined as
     follows:

           1.   TROFF IDIOSYNCRASIES
                Macro Usage
                Passing Space Characters in an Argument
                Trailing Blank Space Characters
                Escaping Special Characters
                Other Possible Pitfalls

           2.   A MANUAL PAGE TEMPLATE

           3.   CONVENTIONS

           4.   TITLE MACROS

           5.   INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS
                What's in a Name...
                General Syntax

           6.   MANUAL DOMAIN
                Addresses
                Author Name
                Arguments
                Configuration Declarations (Section Four Only)
                Command Modifiers
                Defined Variables
                Errno's
                Environment Variables
                Flags
                Function Declarations
                Function Types
                Functions (Library Routines)
                Function Arguments
                Return Values
                Exit Status
                Interactive Commands
                Library Names
                Literals
                Names
                Options
                Pathnames
                Standards
                Variable Types
                Variables
                Manual Page Cross References

           7.   GENERAL TEXT DOMAIN
                AT&T Macro
                BSD Macro
                NetBSD Macro
                FreeBSD Macro
                DragonFly Macro
                OpenBSD Macro
                BSD/OS Macro
                UNIX Macro
                Emphasis Macro
                Font Mode
                Enclosure and Quoting Macros
                No-Op or Normal Text Macro
                No-Space Macro
                Section Cross References
                Symbolics
                Mathematical Symbols
                References and Citations
                Trade Names (or Acronyms and Type Names)
                Extended Arguments

           8.   PAGE STRUCTURE DOMAIN
                Section Headers
                Subsection Headers
                Paragraphs and Line Spacing
                Keeps
                Examples and Displays
                Lists and Columns

           9.   MISCELLANEOUS MACROS

           10.  PREDEFINED STRINGS

           11.  DIAGNOSTICS

           12.  FORMATTING WITH GROFF, TROFF, AND NROFF

           13.  FILES

           14.  SEE ALSO

           15.  BUGS

TROFF IDIOSYNCRASIES         top

     The -mdoc package attempts to simplify the process of writing a man
     page.  Theoretically, one should not have to learn the tricky details
     of GNU troff(1) to use -mdoc; however, there are a few limitations
     which are unavoidable and best gotten out of the way.  And, too, be
     forewarned, this package is not fast.

   Macro Usage
     As in GNU troff(1), a macro is called by placing a ‘.’ (dot character)
     at the beginning of a line followed by the two-character (or three-
     character) name for the macro.  There can be space or tab characters
     between the dot and the macro name.  Arguments may follow the macro
     separated by spaces (but no tabs).  It is the dot character at the
     beginning of the line which causes GNU troff(1) to interpret the next
     two (or more) characters as a macro name.  A single starting dot fol‐
     lowed by nothing is ignored.  To place a ‘.’ (dot character) at the
     beginning of an input line in some context other than a macro invoca‐
     tion, precede the ‘.’ (dot) with the ‘\&’ escape sequence which trans‐
     lates literally to a zero-width space, and is never displayed in the
     output.

     In general, GNU troff(1) macros accept an unlimited number of arguments
     (contrary to other versions of troff which can't handle more than nine
     arguments).  In limited cases, arguments may be continued or extended
     on the next line (See Extended Arguments below).  Almost all macros
     handle quoted arguments (see Passing Space Characters in an Argument
     below).

     Most of the -mdoc general text domain and manual domain macros are spe‐
     cial in that their argument lists are parsed for callable macro names.
     This means an argument on the argument list which matches a general
     text or manual domain macro name (and which is defined to be callable)
     will be executed or called when it is processed.  In this case the
     argument, although the name of a macro, is not preceded by a ‘.’ (dot).
     This makes it possible to nest macros; for example the option macro,
     ‘.Op’, may call the flag and argument macros, ‘Fl’ and ‘Ar’, to specify
     an optional flag with an argument:

           [-s bytes]  is produced by ‘.Op Fl s Ar bytes’

     To prevent a string from being interpreted as a macro name, precede the
     string with the escape sequence ‘\&’:

           [Fl s Ar bytes]  is produced by ‘.Op \&Fl s \&Ar bytes’

     Here the strings ‘Fl’ and ‘Ar’ are not interpreted as macros.  Macros
     whose argument lists are parsed for callable arguments are referred to
     as parsed and macros which may be called from an argument list are
     referred to as callable throughout this document.  This is a technical
     faux pas as almost all of the macros in -mdoc are parsed, but as it was
     cumbersome to constantly refer to macros as being callable and being
     able to call other macros, the term parsed has been used.

     In the following, we call an -mdoc macro which starts a line (with a
     leading dot) a command if this distinction is necessary.

   Passing Space Characters in an Argument
     Sometimes it is desirable to give as an argument a string containing
     one or more blank space characters, say, to specify arguments to com‐
     mands which expect particular arrangement of items in the argument
     list.  Additionally, it makes -mdoc working faster.  For example, the
     function command ‘.Fn’ expects the first argument to be the name of a
     function and any remaining arguments to be function parameters.  As
     ANSI C stipulates the declaration of function parameters in the paren‐
     thesized parameter list, each parameter is guaranteed to be at minimum
     a two word string.  For example, int foo.

     There are two possible ways to pass an argument which contains an
     embedded space.  One way of passing a string containing blank spaces is
     to use the hard or unpaddable space character ‘\ ’, that is, a blank
     space preceded by the escape character ‘\’.  This method may be used
     with any macro but has the side effect of interfering with the adjust‐
     ment of text over the length of a line.  Troff sees the hard space as
     if it were any other printable character and cannot split the string
     into blank or newline separated pieces as one would expect.  This
     method is useful for strings which are not expected to overlap a line
     boundary.  An alternative is to use ‘\~’, a paddable (i.e. stretch‐
     able), unbreakable space (this is a GNU troff(1) extension).  The sec‐
     ond method is to enclose the string with double quotes.

     For example:

           fetch(char *str)  is created by ‘.Fn fetch char\ *str’

           fetch(char *str)  can also be created by ‘.Fn fetch "char *str"’

     If the ‘\’ before the space in the first example or double quotes in
     the second example were omitted, ‘.Fn’ would see three arguments, and
     the result would be:

           fetch(char, *str)

   Trailing Blank Space Characters
     Troff can be confused by blank space characters at the end of a line.
     It is a wise preventive measure to globally remove all blank spaces
     from ⟨blank-space⟩⟨end-of-line⟩ character sequences.  Should the need
     arise to use a blank character at the end of a line, it may be forced
     with an unpaddable space and the ‘\&’ escape character.  For example,
     ‘string\ \&’.

   Escaping Special Characters
     Special characters like the newline character ‘\n’ are handled by
     replacing the ‘\’ with ‘\e’ (e.g. ‘\en’) to preserve the backslash.

   Other Possible Pitfalls
     A warning is emitted when an empty input line is found outside of dis‐
     plays (see below).  Use ‘.sp’ instead.  (Well, it is even better to use
     -mdoc macros to avoid the usage of low-level commands.)

     Leading spaces will cause a break and are output directly.  Avoid this
     behaviour if possible.  Similarly, do not use more than one space char‐
     acter between words in an ordinary text line; contrary to other text
     formatters, they are not replaced with a single space.

     You can't pass ‘"’ directly as an argument.  Use ‘\*[q]’ (or ‘\*q’)
     instead.

     By default, troff(1) inserts two space characters after a punctuation
     mark closing a sentence; characters like ‘)’ or ‘'’ are treated trans‐
     parently, not influencing the sentence-ending behaviour.  To change
     this, insert ‘\&’ before or after the dot:

           The
           .Ql .
           character.
           .Pp
           The
           .Ql \&.
           character.
           .Pp
           .No test .
           test
           .Pp
           .No test.
           test

     gives

           The ‘’.  character

           The ‘.’ character.

           test.  test

           test. test

     As can be seen in the first and third line, -mdoc handles punctuation
     characters specially in macro arguments.  This will be explained in
     section General Syntax below.  In the same way, you have to protect
     trailing full stops of abbreviations with a trailing zero-width space:
     ‘e.g.\&’.

     A comment in the source file of a man page can be either started with
     ‘.\"’ on a single line, ‘\"’ after some input, or ‘\#’ anywhere (the
     latter is a GNU troff(1) extension); the rest of such a line is
     ignored.

A MANUAL PAGE TEMPLATE         top

     The body of a man page is easily constructed from a basic template:

           .\" The following commands are required for all man pages.
           .Dd Month day, year
           .Dt DOCUMENT_TITLE [section number] [architecture/volume]
           .Os [OPERATING_SYSTEM] [version/release]
           .Sh NAME
           .Nm name
           .Nd one line description of name
           .\" This next command is for sections 2 and 3 only.
           .\" .Sh LIBRARY
           .Sh SYNOPSIS
           .Sh DESCRIPTION
           .\" The following commands should be uncommented and
           .\" used where appropriate.
           .\" .Sh IMPLEMENTATION NOTES
           .\" This next command is for sections 2, 3, and 9 only
           .\"     (function return values).
           .\" .Sh RETURN VALUES
           .\" This next command is for sections 1, 6, 7, and 8 only.
           .\" .Sh ENVIRONMENT
           .\" .Sh FILES
           .\" This next command is for sections 1, 6, and 8 only
           .\"     (command return values to the shell).
           .\" .Sh EXIT STATUS
           .\" .Sh EXAMPLES
           .\" This next command is for sections 1, 4, 6, 7, 8, and 9 only
           .\"     (fprintf/stderr type diagnostics).
           .\" .Sh DIAGNOSTICS
           .\" .Sh COMPATIBILITY
           .\" This next command is for sections 2, 3, 4, and 9 only
           .\"     (settings of the errno variable).
           .\" .Sh ERRORS
           .\" .Sh SEE ALSO
           .\" .Sh STANDARDS
           .\" .Sh HISTORY
           .\" .Sh AUTHORS
           .\" .Sh CAVEATS
           .\" .Sh BUGS

     The first items in the template are the commands ‘.Dd’, ‘.Dt’, and
     ‘.Os’; the document date, the operating system the man page or subject
     source is developed or modified for, and the man page title (in upper
     case) along with the section of the manual the page belongs in.  These
     commands identify the page and are discussed below in TITLE MACROS.

     The remaining items in the template are section headers (.Sh); of which
     NAME, SYNOPSIS, and DESCRIPTION are mandatory.  The headers are dis‐
     cussed in PAGE STRUCTURE DOMAIN, after presentation of MANUAL DOMAIN.
     Several content macros are used to demonstrate page layout macros;
     reading about content macros before page layout macros is recommended.

CONVENTIONS         top

     In the description of all macros below, optional arguments are put into
     brackets.  An ellipsis (‘...’) represents zero or more additional argu‐
     ments.  Alternative values for a parameter are separated with ‘|’.  If
     there are alternative values for a mandatory parameter, braces are used
     (together with ‘|’) to enclose the value set.  Meta-variables are spec‐
     ified within angles.

     Example:

           .Xx ⟨foo⟩ {bar1 | bar2} [-test1 [-test2 | -test3]] ...

     Except stated explicitly, all macros are parsed and callable.

     Note that a macro takes effect up to the next nested macro.  For exam‐
     ple, ‘.Ic foo Aq bar’ doesn't produce ‘foo <bar>’ but ‘foo ⟨bar⟩’.
     Consequently, a warning message is emitted for most commands if the
     first argument is a macro itself since it cancels the effect of the
     calling command completely.  Another consequence is that quoting macros
     never insert literal quotes; ‘foo <bar>’ has been produced by ‘.Ic "foo
     <bar>"’.

     Most macros have a default width value which can be used to specify a
     label width (-width) or offset (-offset) for the ‘.Bl’ and ‘.Bd’
     macros.  It is recommended not to use this rather obscure feature to
     avoid dependencies on local modifications of the -mdoc package.

TITLE MACROS         top

     The title macros are part of the page structure domain but are
     presented first and separately for someone who wishes to start writing
     a man page yesterday.  Three header macros designate the document title
     or manual page title, the operating system, and the date of authorship.
     These macros are called once at the very beginning of the document and
     are used to construct headers and footers only.

     .Dt [⟨document title⟩] [⟨section number⟩] [⟨volume⟩]
             The document title is the subject of the man page and must be
             in CAPITALS due to troff limitations.  If omitted, ‘UNTITLED’
             is used.  The section number may be a number in the range
             1, ..., 9 or ‘unass’, ‘draft’, or ‘paper’.  If it is specified,
             and no volume name is given, a default volume name is used.

             Under BSD, the following sections are defined:

             1   BSD General Commands Manual
             2   BSD System Calls Manual
             3   BSD Library Functions Manual
             4   BSD Kernel Interfaces Manual
             5   BSD File Formats Manual
             6   BSD Games Manual
             7   BSD Miscellaneous Information Manual
             8   BSD System Manager's Manual
             9   BSD Kernel Developer's Manual

             A volume name may be arbitrary or one of the following:

             USD     User's Supplementary Documents
             PS1     Programmer's Supplementary Documents
             AMD     Ancestral Manual Documents
             SMM     System Manager's Manual
             URM     User's Reference Manual

             PRM     Programmer's Manual
             KM      Kernel Manual
             IND     Manual Master Index
             LOCAL   Local Manual
             CON     Contributed Software Manual

             For compatibility, ‘MMI’ can be used for ‘IND’, and ‘LOC’ for
             ‘LOCAL’.  Values from the previous table will specify a new
             volume name.  If the third parameter is a keyword designating a
             computer architecture, its value is prepended to the default
             volume name as specified by the second parameter.  By default,
             the following architecture keywords are defined:

                   acorn26, acorn32, algor, alpha, amd64, amiga, amigappc,
                   arc, arm, arm26, arm32, armish, atari, aviion, beagle,
                   bebox, cats, cesfic, cobalt, dreamcast, emips, evbarm,
                   evbmips, evbppc, evbsh3, ews4800mips, hp300, hp700,
                   hpcarm, hpcmips, hpcsh, hppa, hppa64, i386, ia64, ibmnws,
                   iyonix, landisk, loongson, luna68k, luna88k, m68k,
                   mac68k, macppc, mips, mips64, mipsco, mmeye, mvme68k,
                   mvme88k, mvmeppc, netwinder, news68k, newsmips, next68k,
                   ofppc, palm, pc532, playstation2, pmax, pmppc, powerpc,
                   prep, rs6000, sandpoint, sbmips, sgi, sgimips, sh3,
                   shark, socppc, solbourne, sparc, sparc64, sun2, sun3,
                   tahoe, vax, x68k, x86_64, xen, zaurus

             If the section number is neither a numeric expression in the
             range 1 to 9 nor one of the above described keywords, the third
             parameter is used verbatim as the volume name.

             In the following examples, the left (which is identical to the
             right) and the middle part of the manual page header strings
             are shown.  Note how ‘\&’ prevents the digit 7 from being a
             valid numeric expression.

                   .Dt FOO 7       ‘FOO(7)’ ‘BSD Miscellaneous Information
                                   Manual’
                   .Dt FOO 7 bar   ‘FOO(7)’ ‘BSD Miscellaneous Information
                                   Manual’
                   .Dt FOO \&7 bar
                                   ‘FOO(7)’ ‘bar’
                   .Dt FOO 2 i386  ‘FOO(2)’ ‘BSD/i386 System Calls Manual’
                   .Dt FOO "" bar  ‘FOO’ ‘bar’

             Local, OS-specific additions might be found in the file
             mdoc.local; look for strings named ‘volume-ds-XXX’ (for the
             former type) and ‘volume-as-XXX’ (for the latter type); ‘XXX’
             then denotes the keyword to be used with the ‘.Dt’ macro.

             This macro is neither callable nor parsed.

     .Os [⟨operating system⟩] [⟨release⟩]
             If the first parameter is empty, the default ‘BSD’ is used.
             This may be overridden in the local configuration file,
             mdoc.local.  In general, the name of the operating system
             should be the common acronym, e.g. BSD or ATT.  The release
             should be the standard release nomenclature for the system
             specified.  In the following table, the possible second argu‐
             ments for some predefined operating systems are listed.  Simi‐
             lar to ‘.Dt’, local additions might be defined in mdoc.local;
             look for strings named ‘operating-system-XXX-YYY’, where ‘XXX’
             is the acronym for the operating system and ‘YYY’ the release
             ID.

                   ATT        7th, 7, III, 3, V, V.2, V.3, V.4

                   BSD        3, 4, 4.1, 4.2, 4.3, 4.3t, 4.3T, 4.3r, 4.3R,
                              4.4

                   NetBSD     0.8, 0.8a, 0.9, 0.9a, 1.0, 1.0a, 1.1, 1.2,
                              1.2a, 1.2b, 1.2c, 1.2d, 1.2e, 1.3, 1.3a, 1.4,
                              1.4.1, 1.4.2, 1.4.3, 1.5, 1.5.1, 1.5.2, 1.5.3,
                              1.6, 1.6.1, 1.6.2, 1.6.3, 2.0, 2.0.1, 2.0.2,
                              2.0.3, 2.1, 3.0, 3.0.1, 3.0.2, 3.0.3, 3.1,
                              3.1.1, 4.0, 4.0.1, 5.0, 5.0.1, 5.0.2, 5.1,
                              5.1.2, 5.1.3, 5.1.4, 5.2, 5.2.1, 5.2.2, 6.0,
                              6.0.1, 6.0.2, 6.0.3, 6.0.4, 6.0.5, 6.1, 6.1.1,
                              6.1.2, 6.1.3, 6.1.4

                   FreeBSD    1.0, 1.1, 1.1.5, 1.1.5.1, 2.0, 2.0.5, 2.1,
                              2.1.5, 2.1.6, 2.1.7, 2.2, 2.2.1, 2.2.2, 2.2.5,
                              2.2.6, 2.2.7, 2.2.8, 3.0, 3.1, 3.2, 3.3, 3.4,
                              3.5, 4.0, 4.1, 4.1.1, 4.2, 4.3, 4.4, 4.5, 4.6,
                              4.6.2, 4.7, 4.8, 4.9, 4.10, 4.11, 5.0, 5.1,
                              5.2, 5.2.1, 5.3, 5.4, 5.5, 6.0, 6.1, 6.2, 6.3,
                              6.4, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, 8.1, 8.2,
                              8.3, 8.4, 9.0, 9.1, 9.2, 9.3, 10.0

                   OpenBSD    2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8,
                              2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7,
                              3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6,
                              4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5,
                              5.6

                   DragonFly  1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.8, 1.8.1,
                              1.9, 1.10, 1.12, 1.12.2, 1.13, 2.0, 2.2, 2.3,
                              2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 2.9.1, 2.10,
                              2.10.1, 2.11, 2.12, 2.13, 3.0, 3.1, 3.2, 3.3,
                              3.4, 3.5, 3.6, 3.7, 3.8

                   Darwin     8.0.0, 8.1.0, 8.2.0, 8.3.0, 8.4.0, 8.5.0,
                              8.6.0, 8.7.0, 8.8.0, 8.9.0, 8.10.0, 8.11.0,
                              9.0.0, 9.1.0, 9.2.0, 9.3.0, 9.4.0, 9.5.0,
                              9.6.0, 9.7.0, 9.8.0, 10.1.0, 10.2.0, 10.3.0,
                              10.4.0, 10.5.0, 10.6.0, 10.7.0, 10.8.0,
                              11.0.0, 11.1.0, 11.2.0, 11.3.0, 11.4.0,
                              11.5.0, 12.0.0, 12.1.0, 12.2.0, 13.0.0,
                              13.1.0, 13.2.0, 13.3.0, 13.4.0, 14.0.0

             For ATT, an unknown second parameter will be replaced with the
             string UNIX; for the other predefined acronyms it will be
             ignored and a warning message emitted.  Unrecognized arguments
             are displayed as given in the page footer.  For instance, a
             typical footer might be:

                   .Os BSD 4.3

             giving ‘4.3 Berkeley Distribution’, or for a locally produced
             set

                   .Os CS Department

             which will produce ‘CS Department’.

             If the ‘.Os’ macro is not present, the bottom left corner of
             the manual page will be ugly.

             This macro is neither callable nor parsed.

     .Dd [⟨month⟩ ⟨day⟩, ⟨year⟩]
             If ‘Dd’ has no arguments, ‘Epoch’ is used for the date string.
             If it has exactly three arguments, they are concatenated, sepa‐
             rated with unbreakable space:

                   .Dd January 25, 2001

             The month's name shall not be abbreviated.

             With any other number of arguments, the current date is used,
             ignoring the parameters.

             As a special exception, the format

                   .Dd $Mdocdate: ⟨month⟩ ⟨day⟩ ⟨year⟩ $

             is also recognized.  It is used in OpenBSD manuals to automati‐
             cally insert the current date when committing.

             This macro is neither callable nor parsed.

INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS         top

   What's in a Name...
     The manual domain macro names are derived from the day to day informal
     language used to describe commands, subroutines and related files.
     Slightly different variations of this language are used to describe the
     three different aspects of writing a man page.  First, there is the
     description of -mdoc macro command usage.  Second is the description of
     a UNIX command with -mdoc macros, and third, the description of a com‐
     mand to a user in the verbal sense; that is, discussion of a command in
     the text of a man page.

     In the first case, troff(1) macros are themselves a type of command;
     the general syntax for a troff command is:

           .Xx argument1 argument2 ...

     ‘.Xx’ is a macro command, and anything following it are arguments to be
     processed.  In the second case, the description of a UNIX command using
     the content macros is a bit more involved; a typical SYNOPSIS command
     line might be displayed as:

           filter [-flag] ⟨infile⟩ ⟨outfile⟩

     Here, filter is the command name and the bracketed string -flag is a
     flag argument designated as optional by the option brackets.  In -mdoc
     terms, ⟨infile⟩ and ⟨outfile⟩ are called meta arguments; in this exam‐
     ple, the user has to replace the meta expressions given in angle brack‐
     ets with real file names.  Note that in this document meta arguments
     are used to describe -mdoc commands; in most man pages, meta variables
     are not specifically written with angle brackets.  The macros which
     formatted the above example:

           .Nm filter
           .Op Fl flag
           .Ao Ar infile Ac Ao Ar outfile Ac

     In the third case, discussion of commands and command syntax includes
     both examples above, but may add more detail.  The arguments ⟨infile⟩
     and ⟨outfile⟩ from the example above might be referred to as operands
     or file arguments.  Some command line argument lists are quite long:

           make  [-eiknqrstv] [-D variable] [-d flags] [-f makefile] [-I
                 directory] [-j max_jobs] [variable=value] [target ...]

     Here one might talk about the command make and qualify the argument,
     makefile, as an argument to the flag, -f, or discuss the optional file
     operand target.  In the verbal context, such detail can prevent confu‐
     sion, however the -mdoc package does not have a macro for an argument
     to a flag.  Instead the ‘Ar’ argument macro is used for an operand or
     file argument like target as well as an argument to a flag like
     variable.  The make command line was produced from:

           .Nm make
           .Op Fl eiknqrstv
           .Op Fl D Ar variable
           .Op Fl d Ar flags
           .Op Fl f Ar makefile
           .Op Fl I Ar directory
           .Op Fl j Ar max_jobs
           .Op Ar variable Ns = Ns Ar value
           .Bk
           .Op Ar target ...
           .Ek

     The ‘.Bk’ and ‘.Ek’ macros are explained in Keeps.

   General Syntax
     The manual domain and general text domain macros share a similar syntax
     with a few minor deviations; most notably, ‘.Ar’, ‘.Fl’, ‘.Nm’, and
     ‘.Pa’ differ only when called without arguments; and ‘.Fn’ and ‘.Xr’
     impose an order on their argument lists.  All content macros are capa‐
     ble of recognizing and properly handling punctuation, provided each
     punctuation character is separated by a leading space.  If a command is
     given:

           .Ar sptr, ptr),

     The result is:

           sptr, ptr),

     The punctuation is not recognized and all is output in the font used by
     ‘.Ar’.  If the punctuation is separated by a leading white space:

           .Ar sptr , ptr ) ,

     The result is:

           sptr, ptr),

     The punctuation is now recognized and output in the default font dis‐
     tinguishing it from the argument strings.  To remove the special mean‐
     ing from a punctuation character escape it with ‘\&’.

     The following punctuation characters are recognized by -mdoc:

               .         ,         :         ;         (
               )         [         ]         ?         !

     Troff is limited as a macro language, and has difficulty when presented
     with a string containing a member of the mathematical, logical or quo‐
     tation set:

                 {+,-,/,*,%,<,>,<=,>=,=,==,&,`,',"}

     The problem is that troff may assume it is supposed to actually perform
     the operation or evaluation suggested by the characters.  To prevent
     the accidental evaluation of these characters, escape them with ‘\&’.
     Typical syntax is shown in the first content macro displayed below,
     ‘.Ad’.

MANUAL DOMAIN         top

   Addresses
     The address macro identifies an address construct.

           Usage: .Ad ⟨address⟩ ...

                    .Ad addr1           addr1
                    .Ad addr1 .         addr1.
                    .Ad addr1 , file2   addr1, file2
                    .Ad f1 , f2 , f3 :  f1, f2, f3:
                    .Ad addr ) ) ,      addr)),

     The default width is 12n.

   Author Name
     The ‘.An’ macro is used to specify the name of the author of the item
     being documented, or the name of the author of the actual manual page.

           Usage: .An ⟨author name⟩ ...

                    .An "Joe Author"        Joe Author

                    .An "Joe Author" ,      Joe Author,

                    .An "Joe Author" Aq nobody@FreeBSD.org
                                            Joe Author <nobody@FreeBSD.org>

                    .An "Joe Author" ) ) ,  Joe Author)),

     The default width is 12n.

     In the AUTHORS section, the ‘.An’ command causes a line break allowing
     each new name to appear on its own line.  If this is not desirable,

           .An -nosplit

     call will turn this off.  To turn splitting back on, write

           .An -split

   Arguments
     The .Ar argument macro may be used whenever an argument is referenced.
     If called without arguments, the ‘file ...’ string is output.

           Usage: .Ar [⟨argument⟩] ...

                    .Ar              file ...
                    .Ar file1        file1
                    .Ar file1 .      file1.
                    .Ar file1 file2  file1 file2
                    .Ar f1 f2 f3 :   f1 f2 f3:
                    .Ar file ) ) ,   file)),

     The default width is 12n.

   Configuration Declaration (Section Four Only)
     The ‘.Cd’ macro is used to demonstrate a config(8) declaration for a
     device interface in a section four manual.

           Usage: .Cd ⟨argument⟩ ...

                    .Cd "device le0 at scode?"  device le0 at scode?

     In the SYNOPSIS section a ‘.Cd’ command causes a line break before and
     after its arguments are printed.

     The default width is 12n.

   Command Modifiers
     The command modifier is identical to the ‘.Fl’ (flag) command with the
     exception that the ‘.Cm’ macro does not assert a dash in front of every
     argument.  Traditionally flags are marked by the preceding dash, how‐
     ever, some commands or subsets of commands do not use them.  Command
     modifiers may also be specified in conjunction with interactive com‐
     mands such as editor commands.  See Flags.

     The default width is 10n.

   Defined Variables
     A variable (or constant) which is defined in an include file is speci‐
     fied by the macro ‘.Dv’.

           Usage: .Dv ⟨defined variable⟩ ...

                    .Dv MAXHOSTNAMELEN  MAXHOSTNAMELEN
                    .Dv TIOCGPGRP )     TIOCGPGRP)

     The default width is 12n.

   Errno's
     The ‘.Er’ errno macro specifies the error return value for section 2,
     3, and 9 library routines.  The second example below shows ‘.Er’ used
     with the ‘.Bq’ general text domain macro, as it would be used in a sec‐
     tion two manual page.

           Usage: .Er ⟨errno type⟩ ...

                    .Er ENOENT      ENOENT
                    .Er ENOENT ) ;  ENOENT);
                    .Bq Er ENOTDIR  [ENOTDIR]

     The default width is 17n.

   Environment Variables
     The ‘.Ev’ macro specifies an environment variable.

           Usage: .Ev ⟨argument⟩ ...

                    .Ev DISPLAY        DISPLAY
                    .Ev PATH .         PATH.
                    .Ev PRINTER ) ) ,  PRINTER)),

     The default width is 15n.

   Flags
     The ‘.Fl’ macro handles command line flags.  It prepends a dash, ‘-’,
     to the flag.  For interactive command flags, which are not prepended
     with a dash, the ‘.Cm’ (command modifier) macro is identical, but with‐
     out the dash.

           Usage: .Fl ⟨argument⟩ ...

                    .Fl          -
                    .Fl cfv      -cfv
                    .Fl cfv .    -cfv.
                    .Cm cfv .    cfv.
                    .Fl s v t    -s -v -t
                    .Fl - ,      --,
                    .Fl xyz ) ,  -xyz),
                    .Fl |        - |

     The ‘.Fl’ macro without any arguments results in a dash representing
     stdin/stdout.  Note that giving ‘.Fl’ a single dash will result in two
     dashes.

     The default width is 12n.

   Function Declarations
     The ‘.Fd’ macro is used in the SYNOPSIS section with section two or
     three functions.  It is neither callable nor parsed.

           Usage: .Fd ⟨argument⟩ ...

                    .Fd "#include <sys/types.h>"  #include <sys/types.h>

     In the SYNOPSIS section a ‘.Fd’ command causes a line break if a func‐
     tion has already been presented and a break has not occurred.  This
     leaves a nice vertical space in between the previous function call and
     the declaration for the next function.

     The ‘.In’ macro, while in the SYNOPSIS section, represents the #include
     statement, and is the short form of the above example.  It specifies
     the C header file as being included in a C program.  It also causes a
     line break.

     While not in the SYNOPSIS section, it represents the header file
     enclosed in angle brackets.

           Usage: .In ⟨header file⟩

                    .In stdio.h  #include <stdio.h>
                    .In stdio.h  <stdio.h>

   Function Types
     This macro is intended for the SYNOPSIS section.  It may be used any‐
     where else in the man page without problems, but its main purpose is to
     present the function type in kernel normal form for the SYNOPSIS of
     sections two and three (it causes a line break, allowing the function
     name to appear on the next line).

           Usage: .Ft ⟨type⟩ ...

                    .Ft struct stat  struct stat

   Functions (Library Routines)
     The ‘.Fn’ macro is modeled on ANSI C conventions.

           Usage: .Fn ⟨function⟩ [⟨parameter⟩] ...

                    .Fn getchar              getchar()
                    .Fn strlen ) ,           strlen()),
                    .Fn align "char *ptr" ,  align(char *ptr),

     Note that any call to another macro signals the end of the ‘.Fn’ call
     (it will insert a closing parenthesis at that point).

     For functions with many parameters (which is rare), the macros ‘.Fo’
     (function open) and ‘.Fc’ (function close) may be used with ‘.Fa’
     (function argument).

     Example:

           .Ft int
           .Fo res_mkquery
           .Fa "int op"
           .Fa "char *dname"
           .Fa "int class"
           .Fa "int type"
           .Fa "char *data"
           .Fa "int datalen"
           .Fa "struct rrec *newrr"
           .Fa "char *buf"
           .Fa "int buflen"
           .Fc

     Produces:

           int res_mkquery(int op, char *dname, int class, int type,
           char *data, int datalen, struct rrec *newrr, char *buf,
           int buflen)

     In the SYNOPSIS section, the function will always begin at the begin‐
     ning of line.  If there is more than one function presented in the
     SYNOPSIS section and a function type has not been given, a line break
     will occur, leaving a nice vertical space between the current function
     name and the one prior.

     The default width values of ‘.Fn’ and ‘.Fo’ are 12n and 16n, respec‐
     tively.

   Function Arguments
     The ‘.Fa’ macro is used to refer to function arguments (parameters)
     outside of the SYNOPSIS section of the manual or inside the SYNOPSIS
     section if the enclosure macros ‘.Fo’ and ‘.Fc’ instead of ‘.Fn’ are
     used.  ‘.Fa’ may also be used to refer to structure members.

           Usage: .Fa ⟨function argument⟩ ...

                    .Fa d_namlen ) ) ,  d_namlen)),
                    .Fa iov_len         iov_len

     The default width is 12n.

   Return Values
     The ‘.Rv’ macro generates text for use in the RETURN VALUES section.

           Usage: .Rv [-std] [⟨function⟩ ...]

     For example, ‘.Rv -std atexit’ produces:

           The atexit() function returns the value 0 if successful; other‐
           wise the value -1 is returned and the global variable errno is
           set to indicate the error.

     The -std option is valid only for manual page sections 2 and 3.  Cur‐
     rently, this macro does nothing if used without the -std flag.

   Exit Status
     The ‘.Ex’ macro generates text for use in the DIAGNOSTICS section.

           Usage: .Ex [-std] [⟨utility⟩ ...]

     For example, ‘.Ex -std cat’ produces:

           The cat utility exits 0 on success, and >0 if an error occurs.

     The -std option is valid only for manual page sections 1, 6 and 8.
     Currently, this macro does nothing if used without the -std flag.

   Interactive Commands
     The ‘.Ic’ macro designates an interactive or internal command.

           Usage: .Ic ⟨argument⟩ ...

                    .Ic :wq                :wq
                    .Ic "do while {...}"   do while {...}
                    .Ic setenv , unsetenv  setenv, unsetenv

     The default width is 12n.

   Library Names
     The ‘.Lb’ macro is used to specify the library where a particular func‐
     tion is compiled in.

           Usage: .Lb ⟨argument⟩ ...

     Available arguments to ‘.Lb’ and their results are:

           libarchive     Reading and Writing Streaming Archives Library
                          (libarchive, -larchive)
           libarm         ARM Architecture Library (libarm, -larm)
           libarm32       ARM32 Architecture Library (libarm32, -larm32)
           libbluetooth   Bluetooth Library (libbluetooth, -lbluetooth)
           libbsm         Basic Security Module Library (libbsm, -lbsm)
           libc           Standard C Library (libc, -lc)
           libc_r         Reentrant C Library (libc_r, -lc_r)
           libcalendar    Calendar Arithmetic Library (libcalendar,
                          -lcalendar)
           libcam         Common Access Method User Library (libcam, -lcam)
           libcdk         Curses Development Kit Library (libcdk, -lcdk)
           libcipher      FreeSec Crypt Library (libcipher, -lcipher)
           libcompat      Compatibility Library (libcompat, -lcompat)
           libcrypt       Crypt Library (libcrypt, -lcrypt)
           libcurses      Curses Library (libcurses, -lcurses)
           libdevinfo     Device and Resource Information Utility Library
                          (libdevinfo, -ldevinfo)
           libdevstat     Device Statistics Library (libdevstat, -ldevstat)
           libdisk        Interface to Slice and Partition Labels Library
                          (libdisk, -ldisk)
           libdwarf       DWARF Access Library (libdwarf, -ldwarf)
           libedit        Command Line Editor Library (libedit, -ledit)
           libelf         ELF Access Library (libelf, -lelf)
           libevent       Event Notification Library (libevent, -levent)
           libfetch       File Transfer Library for URLs (libfetch, -lfetch)
           libform        Curses Form Library (libform, -lform)
           libgeom        Userland API Library for kernel GEOM subsystem
                          (libgeom, -lgeom)
           libgpib        General-Purpose Instrument Bus (GPIB) library
                          (libgpib, -lgpib)
           libi386        i386 Architecture Library (libi386, -li386)
           libintl        Internationalized Message Handling Library
                          (libintl, -lintl)
           libipsec       IPsec Policy Control Library (libipsec, -lipsec)
           libipx         IPX Address Conversion Support Library (libipx,
                          -lipx)
           libiscsi       iSCSI protocol library (libiscsi, -liscsi)
           libjail        Jail Library (libjail, -ljail)
           libkiconv      Kernel side iconv library (libkiconv, -lkiconv)
           libkse         N:M Threading Library (libkse, -lkse)
           libkvm         Kernel Data Access Library (libkvm, -lkvm)
           libm           Math Library (libm, -lm)
           libm68k        m68k Architecture Library (libm68k, -lm68k)
           libmagic       Magic Number Recognition Library (libmagic,
                          -lmagic)
           libmd          Message Digest (MD4, MD5, etc.) Support Library
                          (libmd, -lmd)
           libmemstat     Kernel Memory Allocator Statistics Library
                          (libmemstat, -lmemstat)
           libmenu        Curses Menu Library (libmenu, -lmenu)
           libnetgraph    Netgraph User Library (libnetgraph, -lnetgraph)
           libnetpgp      Netpgp signing, verification, encryption and
                          decryption (libnetpgp, -lnetpgp)
           libossaudio    OSS Audio Emulation Library (libossaudio,
                          -lossaudio)
           libpam         Pluggable Authentication Module Library (libpam,
                          -lpam)
           libpcap        Packet Capture Library (libpcap, -lpcap)
           libpci         PCI Bus Access Library (libpci, -lpci)
           libpmc         Performance Counters Library (libpmc, -lpmc)
           libposix       POSIX Compatibility Library (libposix, -lposix)
           libprop        Property Container Object Library (libprop,
                          -lprop)
           libpthread     POSIX Threads Library (libpthread, -lpthread)
           libpuffs       puffs Convenience Library (libpuffs, -lpuffs)
           librefuse      File System in Userspace Convenience Library
                          (librefuse, -lrefuse)
           libresolv      DNS Resolver Library (libresolv, -lresolv)
           librpcsec_gss  RPC GSS-API Authentication Library (librpcsec_gss,
                          -lrpcsec_gss)
           librpcsvc      RPC Service Library (librpcsvc, -lrpcsvc)
           librt          POSIX Real-time Library (librt, -lrt)
           libsdp         Bluetooth Service Discovery Protocol User Library
                          (libsdp, -lsdp)
           libssp         Buffer Overflow Protection Library (libssp, -lssp)
           libSystem      System Library (libSystem, -lSystem)
           libtermcap     Termcap Access Library (libtermcap, -ltermcap)
           libterminfo    Terminal Information Library (libterminfo,
                          -lterminfo)
           libthr         1:1 Threading Library (libthr, -lthr)
           libufs         UFS File System Access Library (libufs, -lufs)
           libugidfw      File System Firewall Interface Library (libugidfw,
                          -lugidfw)
           libulog        User Login Record Library (libulog, -lulog)
           libusbhid      USB Human Interface Devices Library (libusbhid,
                          -lusbhid)
           libutil        System Utilities Library (libutil, -lutil)
           libvgl         Video Graphics Library (libvgl, -lvgl)
           libx86_64      x86_64 Architecture Library (libx86_64, -lx86_64)
           libz           Compression Library (libz, -lz)

     Local, OS-specific additions might be found in the file mdoc.local;
     look for strings named ‘str-Lb-XXX’.  ‘XXX’ then denotes the keyword to
     be used with the ‘.Lb’ macro.

     In the LIBRARY section an ‘.Lb’ command causes a line break before and
     after its arguments are printed.

   Literals
     The ‘.Li’ literal macro may be used for special characters, variable
     constants, etc. - anything which should be displayed as it would be
     typed.

           Usage: .Li ⟨argument⟩ ...

                    .Li \en          \n
                    .Li M1 M2 M3 ;   M1 M2 M3;
                    .Li cntrl-D ) ,  cntrl-D),
                    .Li 1024 ...     1024 ...

     The default width is 16n.

   Names
     The ‘.Nm’ macro is used for the document title or subject name.  It has
     the peculiarity of remembering the first argument it was called with,
     which should always be the subject name of the page.  When called with‐
     out arguments, ‘.Nm’ regurgitates this initial name for the sole pur‐
     pose of making less work for the author.  ‘.Nm’ causes a line break
     within the SYNOPSIS section.

     Note: A section two or three document function name is addressed with
     the ‘.Nm’ in the NAME section, and with ‘.Fn’ in the SYNOPSIS and
     remaining sections.  For interactive commands, such as the ‘while’ com‐
     mand keyword in csh(1), the ‘.Ic’ macro should be used.  While ‘.Ic’ is
     nearly identical to ‘.Nm’, it can not recall the first argument it was
     invoked with.

           Usage: .Nm [⟨argument⟩] ...

                    .Nm groff_mdoc  groff_mdoc
                    .Nm \-mdoc      -mdoc
                    .Nm foo ) ) ,   foo)),
                    .Nm :           groff_mdoc:

     The default width is 10n.

   Options
     The ‘.Op’ macro places option brackets around any remaining arguments
     on the command line, and places any trailing punctuation outside the
     brackets.  The macros ‘.Oo’ and ‘.Oc’ (which produce an opening and a
     closing option bracket respectively) may be used across one or more
     lines or to specify the exact position of the closing parenthesis.

           Usage: .Op [⟨option⟩] ...

                    .Op                                []
                    .Op Fl k                           [-k]
                    .Op Fl k ) .                       [-k]).
                    .Op Fl k Ar kookfile               [-k kookfile]
                    .Op Fl k Ar kookfile ,             [-k kookfile],
                    .Op Ar objfil Op Ar corfil         [objfil [corfil]]
                    .Op Fl c Ar objfil Op Ar corfil ,  [-c objfil [corfil]],
                    .Op word1 word2                    [word1 word2]
                    .Li .Op Oo Ao option Ac Oc ...     .Op [⟨option⟩] ...

     Here a typical example of the ‘.Oo’ and ‘.Oc’ macros:

           .Oo
           .Op Fl k Ar kilobytes
           .Op Fl i Ar interval
           .Op Fl c Ar count
           .Oc

     Produces:

           [[-k kilobytes] [-i interval] [-c count]]

     The default width values of ‘.Op’ and ‘.Oo’ are 14n and 10n, respec‐
     tively.

   Pathnames
     The ‘.Pa’ macro formats path or file names.  If called without argu‐
     ments, the ‘~’ string is output, which represents the current user's
     home directory.

           Usage: .Pa [⟨pathname⟩] ...

                    .Pa                    ~
                    .Pa /usr/share         /usr/share
                    .Pa /tmp/fooXXXXX ) .  /tmp/fooXXXXX).

     The default width is 32n.

   Standards
     The ‘.St’ macro replaces standard abbreviations with their formal
     names.

           Usage: .St ⟨abbreviation⟩ ...

     Available pairs for “Abbreviation/Formal Name” are:

     ANSI/ISO C

           -ansiC          ANSI X3.159-1989 (“ANSI C89”)
           -ansiC-89       ANSI X3.159-1989 (“ANSI C89”)
           -isoC           ISO/IEC 9899:1990 (“ISO C90”)
           -isoC-90        ISO/IEC 9899:1990 (“ISO C90”)
           -isoC-99        ISO/IEC 9899:1999 (“ISO C99”)
           -isoC-2011      ISO/IEC 9899:2011 (“ISO C11”)

     POSIX Part 1: System API

           -iso9945-1-90   ISO/IEC 9945-1:1990 (“POSIX.1”)
           -iso9945-1-96   ISO/IEC 9945-1:1996 (“POSIX.1”)
           -p1003.1        IEEE Std 1003.1 (“POSIX.1”)
           -p1003.1-88     IEEE Std 1003.1-1988 (“POSIX.1”)
           -p1003.1-90     ISO/IEC 9945-1:1990 (“POSIX.1”)
           -p1003.1-96     ISO/IEC 9945-1:1996 (“POSIX.1”)
           -p1003.1b-93    IEEE Std 1003.1b-1993 (“POSIX.1”)
           -p1003.1c-95    IEEE Std 1003.1c-1995 (“POSIX.1”)
           -p1003.1g-2000  IEEE Std 1003.1g-2000 (“POSIX.1”)
           -p1003.1i-95    IEEE Std 1003.1i-1995 (“POSIX.1”)
           -p1003.1-2001   IEEE Std 1003.1-2001 (“POSIX.1”)
           -p1003.1-2004   IEEE Std 1003.1-2004 (“POSIX.1”)
           -p1003.1-2008   IEEE Std 1003.1-2008 (“POSIX.1”)

     POSIX Part 2: Shell and Utilities

           -iso9945-2-93   ISO/IEC 9945-2:1993 (“POSIX.2”)
           -p1003.2        IEEE Std 1003.2 (“POSIX.2”)
           -p1003.2-92     IEEE Std 1003.2-1992 (“POSIX.2”)
           -p1003.2a-92    IEEE Std 1003.2a-1992 (“POSIX.2”)

     X/Open

           -susv2          Version 2 of the Single UNIX Specification
                           (“SUSv2”)
           -susv3          Version 3 of the Single UNIX Specification
                           (“SUSv3”)
           -svid4          System V Interface Definition, Fourth Edition
                           (“SVID4”)
           -xbd5           X/Open Base Definitions Issue 5 (“XBD5”)
           -xcu5           X/Open Commands and Utilities Issue 5 (“XCU5”)
           -xcurses4.2     X/Open Curses Issue 4, Version 2 (“XCURSES4.2”)
           -xns5           X/Open Networking Services Issue 5 (“XNS5”)
           -xns5.2         X/Open Networking Services Issue 5.2 (“XNS5.2”)
           -xpg3           X/Open Portability Guide Issue 3 (“XPG3”)
           -xpg4           X/Open Portability Guide Issue 4 (“XPG4”)
           -xpg4.2         X/Open Portability Guide Issue 4, Version 2
                           (“XPG4.2”)
           -xsh5           X/Open System Interfaces and Headers Issue 5
                           (“XSH5”)

     Miscellaneous

           -ieee754        IEEE Std 754-1985
           -iso8601        ISO 8601
           -iso8802-3      ISO/IEC 8802-3:1989

   Variable Types
     The ‘.Vt’ macro may be used whenever a type is referenced.  In the
     SYNOPSIS section, it causes a line break (useful for old style variable
     declarations).

           Usage: .Vt ⟨type⟩ ...

                    .Vt extern char *optarg ;  extern char *optarg;
                    .Vt FILE *                 FILE *

   Variables
     Generic variable reference.

           Usage: .Va ⟨variable⟩ ...

                    .Va count             count
                    .Va settimer ,        settimer,
                    .Va "int *prt" ) :    int *prt):
                    .Va "char s" ] ) ) ,  char s])),

     The default width is 12n.

   Manual Page Cross References
     The ‘.Xr’ macro expects the first argument to be a manual page name.
     The optional second argument, if a string (defining the manual sec‐
     tion), is put into parentheses.

           Usage: .Xr ⟨man page name⟩ [⟨section⟩] ...

                    .Xr mdoc        mdoc
                    .Xr mdoc ,      mdoc,
                    .Xr mdoc 7      mdoc(7)
                    .Xr xinit 1x ;  xinit(1x);

     The default width is 10n.

GENERAL TEXT DOMAIN         top

   AT&T Macro
           Usage: .At [⟨version⟩] ...

                    .At       AT&T UNIX
                    .At v6 .  Version 6 AT&T UNIX.

     The following values for ⟨version⟩ are possible:

           32v, v1, v2, v3, v4, v5, v6, v7, III, V, V.1, V.2, V.3, V.4

   BSD Macro
           Usage: .Bx {-alpha | -beta | -devel} ...
                  .Bx [⟨version⟩ [⟨release⟩]] ...

                    .Bx         BSD
                    .Bx 4.3 .   4.3BSD.
                    .Bx -devel  BSD (currently under development)

     ⟨version⟩ will be prepended to the string ‘BSD’.  The following values
     for ⟨release⟩ are possible:

           Reno, reno, Tahoe, tahoe, Lite, lite, Lite2, lite2

   NetBSD Macro
           Usage: .Nx [⟨version⟩] ...

                    .Nx        NetBSD
                    .Nx 1.4 .  NetBSD 1.4.

     For possible values of ⟨version⟩ see the description of the ‘.Os’ com‐
     mand above in section TITLE MACROS.

   FreeBSD Macro
           Usage: .Fx [⟨version⟩] ...

                    .Fx        FreeBSD
                    .Fx 2.2 .  FreeBSD 2.2.

     For possible values of ⟨version⟩ see the description of the ‘.Os’ com‐
     mand above in section TITLE MACROS.

   DragonFly Macro
           Usage: .Dx [⟨version⟩] ...

                    .Dx        DragonFly
                    .Dx 1.4 .  DragonFly 1.4.

     For possible values of ⟨version⟩ see the description of the ‘.Os’ com‐
     mand above in section TITLE MACROS.

   OpenBSD Macro
           Usage: .Ox [⟨version⟩] ...

                    .Ox 1.0  OpenBSD 1.0

   BSD/OS Macro
           Usage: .Bsx [⟨version⟩] ...

                    .Bsx 1.0  BSD/OS 1.0

   UNIX Macro
           Usage: .Ux ...

                    .Ux  UNIX

   Emphasis Macro
     Text may be stressed or emphasized with the ‘.Em’ macro.  The usual
     font for emphasis is italic.

           Usage: .Em ⟨argument⟩ ...

                    .Em does not          does not
                    .Em exceed 1024 .     exceed 1024.
                    .Em vide infra ) ) ,  vide infra)),

     The default width is 10n.

   Font Mode
     The ‘.Bf’ font mode must be ended with the ‘.Ef’ macro (the latter
     takes no arguments).  Font modes may be nested within other font modes.

     ‘.Bf’ has the following syntax:

           .Bf ⟨font mode⟩

     ⟨font mode⟩ must be one of the following three types:

           Em | -emphasis  Same as if the ‘.Em’ macro was used for the
                           entire block of text.
           Li | -literal   Same as if the ‘.Li’ macro was used for the
                           entire block of text.
           Sy | -symbolic  Same as if the ‘.Sy’ macro was used for the
                           entire block of text.

     Both macros are neither callable nor parsed.

   Enclosure and Quoting Macros
     The concept of enclosure is similar to quoting.  The object being to
     enclose one or more strings between a pair of characters like quotes or
     parentheses.  The terms quoting and enclosure are used interchangeably
     throughout this document.  Most of the one-line enclosure macros end in
     small letter ‘q’ to give a hint of quoting, but there are a few irregu‐
     larities.  For each enclosure macro there is also a pair of open and
     close macros which end in small letters ‘o’ and ‘c’ respectively.

     Quote   Open   Close   Function                  Result
     .Aq     .Ao    .Ac     Angle Bracket Enclosure   <string>
     .Bq     .Bo    .Bc     Bracket Enclosure         [string]
     .Brq    .Bro   .Brc    Brace Enclosure           {string}
     .Dq     .Do    .Dc     Double Quote              "string"
     .Eq     .Eo    .Ec     Enclose String (in XX)    XXstring
     .Pq     .Po    .Pc     Parenthesis Enclosure     (string)
     .Ql                    Quoted Literal            “string” or string
     .Qq     .Qo    .Qc     Straight Double Quote     "string"
     .Sq     .So    .Sc     Single Quote              'string'

     All macros ending with ‘q’ and ‘o’ have a default width value of 12n.

     .Eo, .Ec  These macros expect the first argument to be the opening and
               closing strings respectively.

     .Es, .En  Due to the nine-argument limit in the original troff program
               two other macros have been implemented which are now rather
               obsolete: ‘.Es’ takes the first and second parameter as the
               left and right enclosure string, which are then used to
               enclose the arguments of ‘.En’.  The default width value is
               12n for both macros.

     .Eq       The first and second arguments of this macro are the opening
               and closing strings respectively, followed by the arguments
               to be enclosed.

     .Ql       The quoted literal macro behaves differently in troff and
               nroff mode.  If formatted with nroff, a quoted literal is
               always quoted.  If formatted with troff, an item is only
               quoted if the width of the item is less than three constant
               width characters.  This is to make short strings more visible
               where the font change to literal (constant width) is less
               noticeable.

               The default width is 16n.

     .Pf       The prefix macro suppresses the whitespace between its first
               and second argument:

                     .Pf ( Fa name2  (name2

               The default width is 12n.

               The ‘.Ns’ macro (see below) performs the analogous suffix
               function.

     .Ap       The ‘.Ap’ macro inserts an apostrophe and exits any special
               text modes, continuing in ‘.No’ mode.

     Examples of quoting:

           .Aq                      ⟨⟩
           .Aq Pa ctype.h ) ,       ⟨ctype.h⟩),
           .Bq                      []
           .Bq Em Greek , French .  [Greek, French].
           .Dq                      “”
           .Dq string abc .         “string abc”.
           .Dq ´^[A-Z]´             “´^[A-Z]´”
           .Ql man mdoc             ‘man mdoc’
           .Qq                      ""
           .Qq string ) ,           "string"),
           .Qq string Ns ),         "string),"
           .Sq                      ‘’
           .Sq string               ‘string’
           .Em or Ap ing            or'ing

     For a good example of nested enclosure macros, see the ‘.Op’ option
     macro.  It was created from the same underlying enclosure macros as
     those presented in the list above.  The ‘.Xo’ and ‘.Xc’ extended argu‐
     ment list macros are discussed below.

   No-Op or Normal Text Macro
     The ‘.No’ macro can be used in a macro command line for parameters
     which should not be formatted.  Be careful to add ‘\&’ to the word ‘No’
     if you really want that English word (and not the macro) as a parame‐
     ter.

           Usage: .No ⟨argument⟩ ...

                    .No test Ta with Ta tabs  test     with     tabs

     The default width is 12n.

   No-Space Macro
     The ‘.Ns’ macro suppresses insertion of a space between the current
     position and its first parameter.  For example, it is useful for old
     style argument lists where there is no space between the flag and argu‐
     ment:

           Usage: ... ⟨argument⟩ Ns [⟨argument⟩] ...
                  .Ns ⟨argument⟩ ...

                    .Op Fl I Ns Ar directory  [-Idirectory]

     Note: The ‘.Ns’ macro always invokes the ‘.No’ macro after eliminating
     the space unless another macro name follows it.  If used as a command
     (i.e., the second form above in the ‘Usage’ line), ‘.Ns’ is identical
     to ‘.No’.

   Section Cross References
     The ‘.Sx’ macro designates a reference to a section header within the
     same document.

           Usage: .Sx ⟨section reference⟩ ...

                    .Sx FILES  FILES

     The default width is 16n.

   Symbolics
     The symbolic emphasis macro is generally a boldface macro in either the
     symbolic sense or the traditional English usage.

           Usage: .Sy ⟨symbol⟩ ...

                    .Sy Important Notice  Important Notice

     The default width is 6n.

   Mathematical Symbols
     Use this macro for mathematical symbols and similar things.

           Usage: .Ms ⟨math symbol⟩ ...

                    .Ms sigma  sigma

     The default width is 6n.

   References and Citations
     The following macros make a modest attempt to handle references.  At
     best, the macros make it convenient to manually drop in a subset of
     refer(1) style references.

           .Rs     Reference start (does not take arguments).  Causes a line
                   break in the SEE ALSO section and begins collection of
                   reference information until the reference end macro is
                   read.
           .Re     Reference end (does not take arguments).  The reference
                   is printed.
           .%A     Reference author name; one name per invocation.
           .%B     Book title.
           .%C     City/place.
           .%D     Date.
           .%I     Issuer/publisher name.
           .%J     Journal name.
           .%N     Issue number.
           .%O     Optional information.
           .%P     Page number.
           .%Q     Corporate or foreign author.
           .%R     Report name.
           .%T     Title of article.
           .%U     Optional hypertext reference.
           .%V     Volume.

     Macros beginning with ‘%’ are not callable but accept multiple argu‐
     ments in the usual way.  Only the ‘.Tn’ macro is handled properly as a
     parameter; other macros will cause strange output.  ‘.%B’ and ‘.%T’ can
     be used outside of the ‘.Rs/.Re’ environment.

     Example:

           .Rs
           .%A "Matthew Bar"
           .%A "John Foo"
           .%T "Implementation Notes on foobar(1)"
           .%R "Technical Report ABC-DE-12-345"
           .%Q "Drofnats College"
           .%C "Nowhere"
           .%D "April 1991"
           .Re

     produces

           Matthew Bar and John Foo, Implementation Notes on foobar(1),
           Technical Report ABC-DE-12-345, Drofnats College, Nowhere, April
           1991.

   Trade Names (or Acronyms and Type Names)
     The trade name macro prints its arguments in a smaller font.  Its
     intended use is to imitate a small caps fonts for uppercase acronyms.

           Usage: .Tn ⟨symbol⟩ ...

                    .Tn DEC    DEC
                    .Tn ASCII  ASCII

     The default width is 10n.

   Extended Arguments
     The .Xo and .Xc macros allow one to extend an argument list on a macro
     boundary for the ‘.It’ macro (see below).  Note that .Xo and .Xc are
     implemented similarly to all other macros opening and closing an enclo‐
     sure (without inserting characters, of course).  This means that the
     following is true for those macros also.

     Here is an example of ‘.Xo’ using the space mode macro to turn spacing
     off:

           .Sm off
           .It Xo Sy I Ar operation
           .No \en Ar count No \en
           .Xc
           .Sm on

     produces

           Ioperation\ncount\n

     Another one:

           .Sm off
           .It Cm S No / Ar old_pattern Xo
           .No / Ar new_pattern
           .No / Op Cm g
           .Xc
           .Sm on

     produces

           S/old_pattern/new_pattern/[g]

     Another example of ‘.Xo’ and enclosure macros: Test the value of a
     variable.

           .It Xo
           .Ic .ifndef
           .Oo \&! Oc Ns Ar variable Oo
           .Ar operator variable ...
           .Oc Xc

     produces

           .ifndef [!]variable [operator variable ...]

PAGE STRUCTURE DOMAIN         top

   Section Headers
     The following ‘.Sh’ section header macros are required in every man
     page.  The remaining section headers are recommended at the discretion
     of the author writing the manual page.  The ‘.Sh’ macro is parsed but
     not generally callable.  It can be used as an argument in a call to
     ‘.Sh’ only; it then reactivates the default font for ‘.Sh’.

     The default width is 8n.

     .Sh NAME           The ‘.Sh NAME’ macro is mandatory.  If not speci‐
                        fied, headers, footers and page layout defaults will
                        not be set and things will be rather unpleasant.
                        The NAME section consists of at least three items.
                        The first is the ‘.Nm’ name macro naming the subject
                        of the man page.  The second is the name description
                        macro, ‘.Nd’, which separates the subject name from
                        the third item, which is the description.  The
                        description should be the most terse and lucid pos‐
                        sible, as the space available is small.

                        ‘.Nd’ first prints ‘-’, then all its arguments.

     .Sh LIBRARY        This section is for section two and three function
                        calls.  It should consist of a single ‘.Lb’ macro
                        call; see Library Names.

     .Sh SYNOPSIS       The SYNOPSIS section describes the typical usage of
                        the subject of a man page.  The macros required are
                        either ‘.Nm’, ‘.Cd’, or ‘.Fn’ (and possibly ‘.Fo’,
                        ‘.Fc’, ‘.Fd’, and ‘.Ft’).  The function name macro
                        ‘.Fn’ is required for manual page sections 2 and 3;
                        the command and general name macro ‘.Nm’ is required
                        for sections 1, 5, 6, 7, and 8.  Section 4 manuals
                        require a ‘.Nm’, ‘.Fd’ or a ‘.Cd’ configuration
                        device usage macro.  Several other macros may be
                        necessary to produce the synopsis line as shown
                        below:

                              cat [-benstuv] [-] file ...

                        The following macros were used:

                              .Nm cat
                              .Op Fl benstuv
                              .Op Fl
                              .Ar

     .Sh DESCRIPTION    In most cases the first text in the DESCRIPTION sec‐
                        tion is a brief paragraph on the command, function
                        or file, followed by a lexical list of options and
                        respective explanations.  To create such a list, the
                        ‘.Bl’ (begin list), ‘.It’ (list item) and ‘.El’ (end
                        list) macros are used (see Lists and Columns below).

     .Sh IMPLEMENTATION NOTES
                        Implementation specific information should be placed
                        here.

     .Sh RETURN VALUES  Sections 2, 3 and 9 function return values should go
                        here.  The ‘.Rv’ macro may be used to generate text
                        for use in the RETURN VALUES section for most sec‐
                        tion 2 and 3 library functions; see Return Values.

     The following ‘.Sh’ section headers are part of the preferred manual
     page layout and must be used appropriately to maintain consistency.
     They are listed in the order in which they would be used.

     .Sh ENVIRONMENT    The ENVIRONMENT section should reveal any related
                        environment variables and clues to their behavior
                        and/or usage.

     .Sh FILES          Files which are used or created by the man page sub‐
                        ject should be listed via the ‘.Pa’ macro in the
                        FILES section.

     .Sh EXAMPLES       There are several ways to create examples.  See the
                        EXAMPLES section below for details.

     .Sh DIAGNOSTICS    Diagnostic messages from a command should be placed
                        in this section.  The ‘.Ex’ macro may be used to
                        generate text for use in the DIAGNOSTICS section for
                        most section 1, 6 and 8 commands; see Exit Status.

     .Sh COMPATIBILITY  Known compatibility issues (e.g. deprecated options
                        or parameters) should be listed here.

     .Sh ERRORS         Specific error handling, especially from library
                        functions (man page sections 2, 3, and 9) should go
                        here.  The ‘.Er’ macro is used to specify an error
                        (errno).

     .Sh SEE ALSO       References to other material on the man page topic
                        and cross references to other relevant man pages
                        should be placed in the SEE ALSO section.  Cross
                        references are specified using the ‘.Xr’ macro.
                        Currently refer(1) style references are not accommo‐
                        dated.

                        It is recommended that the cross references are
                        sorted on the section number, then alphabetically on
                        the names within a section, and placed in that order
                        and comma separated.  Example:

                        ls(1), ps(1), group(5), passwd(5)

     .Sh STANDARDS      If the command, library function or file adheres to
                        a specific implementation such as IEEE Std 1003.2
                        (“POSIX.2”) or ANSI X3.159-1989 (“ANSI C89”) this
                        should be noted here.  If the command does not
                        adhere to any standard, its history should be noted
                        in the HISTORY section.

     .Sh HISTORY        Any command which does not adhere to any specific
                        standards should be outlined historically in this
                        section.

     .Sh AUTHORS        Credits should be placed here.  Use the ‘.An’ macro
                        for names and the ‘.Aq’ macro for e-mail addresses
                        within optional contact information.  Explicitly
                        indicate whether the person authored the initial
                        manual page or the software or whatever the person
                        is being credited for.

     .Sh BUGS           Blatant problems with the topic go here.

     User-specified ‘.Sh’ sections may be added; for example, this section
     was set with:

                    .Sh "PAGE STRUCTURE DOMAIN"

   Subsection Headers
     Subsection headers have exactly the same syntax as section headers:
     ‘.Ss’ is parsed but not generally callable.  It can be used as an argu‐
     ment in a call to ‘.Ss’ only; it then reactivates the default font for
     ‘.Ss’.

     The default width is 8n.

   Paragraphs and Line Spacing
     .Pp  The ‘.Pp’ paragraph command may be used to specify a line space
          where necessary.  The macro is not necessary after a ‘.Sh’ or
          ‘.Ss’ macro or before a ‘.Bl’ or ‘.Bd’ macro (which both assert a
          vertical distance unless the -compact flag is given).

          The macro is neither callable nor parsed and takes no arguments;
          an alternative name is ‘.Lp’.

   Keeps
     The only keep that is implemented at this time is for words.  The
     macros are ‘.Bk’ (begin keep) and ‘.Ek’ (end keep).  The only option
     that ‘.Bk’ accepts currently is -words (this is also the default if no
     option is given) which is useful for preventing line breaks in the mid‐
     dle of options.  In the example for the make command line arguments
     (see What's in a Name), the keep prevented nroff from placing up the
     flag and the argument on separate lines.

     Both macros are neither callable nor parsed.

     More work needs to be done with the keep macros; specifically, a -line
     option should be added.

   Examples and Displays
     There are seven types of displays.

     .D1  (This is D-one.)  Display one line of indented text.  This macro
          is parsed but not callable.

                -ldghfstru

          The above was produced by: .D1 Fl ldghfstru.

     .Dl  (This is D-ell.)  Display one line of indented literal text.  The
          ‘.Dl’ example macro has been used throughout this file.  It allows
          the indentation (display) of one line of text.  Its default font
          is set to constant width (literal).  ‘.Dl’ is parsed but not
          callable.

                % ls -ldg /usr/local/bin

          The above was produced by: .Dl % ls \-ldg /usr/local/bin.

     .Bd  Begin display.  The ‘.Bd’ display must be ended with the ‘.Ed’
          macro.  It has the following syntax:

                .Bd {-literal | -filled | -unfilled | -ragged | -centered}
                     [-offset ⟨string⟩] [-file ⟨file name⟩] [-compact]

          -ragged            Fill, but do not adjust the right margin (only
                             left-justify).
          -centered          Center lines between the current left and right
                             margin.  Note that each single line is cen‐
                             tered.
          -unfilled          Do not fill; display a block of text as typed,
                             using line breaks as specified by the user.
                             This can produce overlong lines without warning
                             messages.
          -filled            Display a filled block.  The block of text is
                             formatted (i.e., the text is justified on both
                             the left and right side).
          -literal           Display block with literal font (usually fixed-
                             width).  Useful for source code or simple
                             tabbed or spaced text.
          -file file name⟩  The file whose name follows the -file flag is
                             read and displayed before any data enclosed
                             with ‘.Bd’ and ‘.Ed’, using the selected dis‐
                             play type.  Any troff/-mdoc commands in the
                             file will be processed.
          -offset string⟩   If -offset is specified with one of the follow‐
                             ing strings, the string is interpreted to indi‐
                             cate the level of indentation for the forthcom‐
                             ing block of text:

                             left        Align block on the current left
                                         margin; this is the default mode of
                                         ‘.Bd’.
                             center      Supposedly center the block.  At
                                         this time unfortunately, the block
                                         merely gets left aligned about an
                                         imaginary center margin.
                             indent      Indent by one default indent value
                                         or tab.  The default indent value
                                         is also used for the ‘.D1’ and
                                         ‘.Dl’ macros, so one is guaranteed
                                         the two types of displays will line
                                         up.  The indentation value is nor‐
                                         mally set to 6n or about two thirds
                                         of an inch (six constant width
                                         characters).
                             indent-two  Indent two times the default indent
                                         value.
                             right       This left aligns the block about
                                         two inches from the right side of
                                         the page.  This macro needs work
                                         and perhaps may never do the right
                                         thing within troff.

                             If ⟨string⟩ is a valid numeric expression
                             instead (with a scale indicator other thanu’), use that value for indentation.  The most
                             useful scale indicators are ‘m’ and ‘n’, speci‐
                             fying the so-called Em and En square.  This is
                             approximately the width of the letters ‘m’ and
                             ‘n’ respectively of the current font (for nroff
                             output, both scale indicators give the same
                             values).  If ⟨string⟩ isn't a numeric expres‐
                             sion, it is tested whether it is an -mdoc macro
                             name, and the default offset value associated
                             with this macro is used.  Finally, if all tests
                             fail, the width of ⟨string⟩ (typeset with a
                             fixed-width font) is taken as the offset.
          -compact           Suppress insertion of vertical space before
                             begin of display.

     .Ed  End display (takes no arguments).

   Lists and Columns
     There are several types of lists which may be initiated with the ‘.Bl’
     begin-list macro.  Items within the list are specified with the ‘.It’
     item macro, and each list must end with the ‘.El’ macro.  Lists may be
     nested within themselves and within displays.  The use of columns
     inside of lists or lists inside of columns is unproven.

     In addition, several list attributes may be specified such as the width
     of a tag, the list offset, and compactness (blank lines between items
     allowed or disallowed).  Most of this document has been formatted with
     a tag style list (-tag).

     It has the following syntax forms:

           .Bl {-hang | -ohang | -tag | -diag | -inset} [-width ⟨string⟩]
                [-offset ⟨string⟩] [-compact]
           .Bl -column [-offset ⟨string⟩] ⟨string1⟩ ⟨string2⟩ ...
           .Bl {-item | -enum [-nested] | -bullet | -hyphen | -dash}
                [-offset ⟨string⟩] [-compact]

     And now a detailed description of the list types.

     -bullet  A bullet list.

                    .Bl -bullet -offset indent -compact
                    .It
                    Bullet one goes here.
                    .It
                    Bullet two here.
                    .El

              Produces:

                    ·   Bullet one goes here.
                    ·   Bullet two here.

     -dash (or -hyphen)
              A dash list.

                    .Bl -dash -offset indent -compact
                    .It
                    Dash one goes here.
                    .It
                    Dash two here.
                    .El

              Produces:

                    -   Dash one goes here.
                    -   Dash two here.

     -enum    An enumerated list.

                    .Bl -enum -offset indent -compact
                    .It
                    Item one goes here.
                    .It
                    And item two here.
                    .El

              The result:

                    1.   Item one goes here.
                    2.   And item two here.

              If you want to nest enumerated lists, use the -nested flag
              (starting with the second-level list):

                    .Bl -enum -offset indent -compact
                    .It
                    Item one goes here
                    .Bl -enum -nested -compact
                    .It
                    Item two goes here.
                    .It
                    And item three here.
                    .El
                    .It
                    And item four here.
                    .El

              Result:

                    1.   Item one goes here.
                         1.1.   Item two goes here.
                         1.2.   And item three here.
                    2.   And item four here.

     -item    A list of type -item without list markers.

                    .Bl -item -offset indent
                    .It
                    Item one goes here.
                    Item one goes here.
                    Item one goes here.
                    .It
                    Item two here.
                    Item two here.
                    Item two here.
                    .El

              Produces:

                    Item one goes here.  Item one goes here.  Item one goes
                    here.

                    Item two here.  Item two here.  Item two here.

     -tag     A list with tags.  Use -width to specify the tag width.

                    SL    sleep time of the process (seconds blocked)
                    PAGEIN
                          number of disk I/O's resulting from references by
                          the process to pages not loaded in core.
                    UID   numerical user-id of process owner
                    PPID  numerical id of parent of process priority (non-
                          positive when in non-interruptible wait)

              The raw text:

                    .Bl -tag -width "PPID" -compact -offset indent
                    .It SL
                    sleep time of the process (seconds blocked)
                    .It PAGEIN
                    number of disk
                    .Tn I/O Ns 's
                    resulting from references by the process
                    to pages not loaded in core.
                    .It UID
                    numerical user-id of process owner
                    .It PPID
                    numerical id of parent of process priority
                    (non-positive when in non-interruptible wait)
                    .El

     -diag    Diag lists create section four diagnostic lists and are simi‐
              lar to inset lists except callable macros are ignored.  The
              -width flag is not meaningful in this context.

              Example:

                    .Bl -diag
                    .It You can't use Sy here.
                    The message says all.
                    .El

              produces

              You can't use Sy here.  The message says all.

     -hang    A list with hanging tags.

                    Hanged  labels appear similar to tagged lists when the
                            label is smaller than the label width.

                    Longer hanged list labels blend into the paragraph
                            unlike tagged paragraph labels.

              And the unformatted text which created it:

                    .Bl -hang -offset indent
                    .It Em Hanged
                    labels appear similar to tagged lists when the
                    label is smaller than the label width.
                    .It Em Longer hanged list labels
                    blend into the paragraph unlike
                    tagged paragraph labels.
                    .El

     -ohang   Lists with overhanging tags do not use indentation for the
              items; tags are written to a separate line.

                    SL
                    sleep time of the process (seconds blocked)

                    PAGEIN
                    number of disk I/O's resulting from references by the
                    process to pages not loaded in core.

                    UID
                    numerical user-id of process owner

                    PPID
                    numerical id of parent of process priority (non-positive
                    when in non-interruptible wait)

              The raw text:

                    .Bl -ohang -offset indent
                    .It Sy SL
                    sleep time of the process (seconds blocked)
                    .It Sy PAGEIN
                    number of disk
                    .Tn I/O Ns 's
                    resulting from references by the process
                    to pages not loaded in core.
                    .It Sy UID
                    numerical user-id of process owner
                    .It Sy PPID
                    numerical id of parent of process priority
                    (non-positive when in non-interruptible wait)
                    .El

     -inset   Here is an example of inset labels:

                    Tag The tagged list (also called a tagged paragraph) is
                    the most common type of list used in the Berkeley manu‐
                    als.  Use a -width attribute as described below.

                    Diag Diag lists create section four diagnostic lists and
                    are similar to inset lists except callable macros are
                    ignored.

                    Hang Hanged labels are a matter of taste.

                    Ohang Overhanging labels are nice when space is con‐
                    strained.

                    Inset Inset labels are useful for controlling blocks of
                    paragraphs and are valuable for converting -mdoc manuals
                    to other formats.

              Here is the source text which produced the above example:

                    .Bl -inset -offset indent
                    .It Em Tag
                    The tagged list (also called a tagged paragraph)
                    is the most common type of list used in the
                    Berkeley manuals.
                    .It Em Diag
                    Diag lists create section four diagnostic lists
                    and are similar to inset lists except callable
                    macros are ignored.
                    .It Em Hang
                    Hanged labels are a matter of taste.
                    .It Em Ohang
                    Overhanging labels are nice when space is constrained.
                    .It Em Inset
                    Inset labels are useful for controlling blocks of
                    paragraphs and are valuable for converting
                    .Nm -mdoc
                    manuals to other formats.
                    .El

     -column  This list type generates multiple columns.  The number of col‐
              umns and the width of each column is determined by the argu‐
              ments to the -column list, ⟨string1⟩, ⟨string2⟩, etc.  If
              ⟨stringN⟩ starts with a ‘.’ (dot) immediately followed by a
              valid -mdoc macro name, interpret ⟨stringN⟩ and use the width
              of the result.  Otherwise, the width of ⟨stringN⟩ (typeset
              with a fixed-width font) is taken as the Nth column width.

              Each ‘.It’ argument is parsed to make a row, each column
              within the row is a separate argument separated by a tab or
              the ‘.Ta’ macro.

              The table:

                    String    Nroff    Troff
                    <=        <=       ≤
                    >=        >=       ≥

              was produced by:

              .Bl -column -offset indent ".Sy String" ".Sy Nroff" ".Sy Troff"
              .It Sy String Ta Sy Nroff Ta Sy Troff
              .It Li <= Ta <= Ta \*(<=
              .It Li >= Ta >= Ta \*(>=
              .El

              Don't abuse this list type!  For more complicated cases it
              might be far better and easier to use tbl(1), the table pre‐
              processor.

     Other keywords:

     -width string⟩   If ⟨string⟩ starts with a ‘.’ (dot) immediately fol‐
                       lowed by a valid -mdoc macro name, interpret ⟨string⟩
                       and use the width of the result.  Almost all lists in
                       this document use this option.

                       Example:

                             .Bl -tag -width ".Fl test Ao Ar string Ac"
                             .It Fl test Ao Ar string Ac
                             This is a longer sentence to show how the
                             .Fl width
                             flag works in combination with a tag list.
                             .El

                       gives:

                       -test string⟩  This is a longer sentence to show how
                                       the -width flag works in combination
                                       with a tag list.

                       (Note that the current state of -mdoc is saved before
                       ⟨string⟩ is interpreted; afterwards, all variables
                       are restored again.  However, boxes (used for enclo‐
                       sures) can't be saved in GNU troff(1); as a conse‐
                       quence, arguments must always be balanced to avoid
                       nasty errors.  For example, do not write ‘.Ao Ar
                       string’ but ‘.Ao Ar string Xc’ instead if you really
                       need only an opening angle bracket.)

                       Otherwise, if ⟨string⟩ is a valid numeric expression
                       (with a scale indicator other thanu’), use that
                       value for indentation.  The most useful scale indica‐
                       tors are ‘m’ and ‘n’, specifying the so-called Em and
                       En square.  This is approximately the width of the
                       letters ‘m’ and ‘n’ respectively of the current font
                       (for nroff output, both scale indicators give the
                       same values).  If ⟨string⟩ isn't a numeric expres‐
                       sion, it is tested whether it is an -mdoc macro name,
                       and the default width value associated with this
                       macro is used.  Finally, if all tests fail, the width
                       of ⟨string⟩ (typeset with a fixed-width font) is
                       taken as the width.

                       If a width is not specified for the tag list type,
                       every time ‘.It’ is invoked, an attempt is made to
                       determine an appropriate width.  If the first argu‐
                       ment to ‘.It’ is a callable macro, the default width
                       for that macro will be used; otherwise, the default
                       width of ‘.No’ is used.

     -offset string⟩  If ⟨string⟩ is indent, a default indent value (nor‐
                       mally set to 6n, similar to the value used in ‘.Dl’
                       or ‘.Bd’) is used.  If ⟨string⟩ is a valid numeric
                       expression instead (with a scale indicator other thanu’), use that value for indentation.  The most use‐
                       ful scale indicators are ‘m’ and ‘n’, specifying the
                       so-called Em and En square.  This is approximately
                       the width of the letters ‘m’ and ‘n’ respectively of
                       the current font (for nroff output, both scale indi‐
                       cators give the same values).  If ⟨string⟩ isn't a
                       numeric expression, it is tested whether it is an
                       -mdoc macro name, and the default offset value asso‐
                       ciated with this macro is used.  Finally, if all
                       tests fail, the width of ⟨string⟩ (typeset with a
                       fixed-width font) is taken as the offset.

     -compact          Suppress insertion of vertical space before the list
                       and between list items.

MISCELLANEOUS MACROS         top

     Here a list of the remaining macros which do not fit well into one of
     the above sections.  We couldn't find real examples for the following
     macros: ‘.Me’ and ‘.Ot’.  They are documented here for completeness -
     if you know how to use them properly please send a mail to
     bug-groff@gnu.org (including an example).

     .Bt  prints

                is currently in beta test.

          It is neither callable nor parsed and takes no arguments.

     .Fr

                Usage: .Fr ⟨function return value⟩ ...

          Don't use this macro.  It allows a break right before the return
          value (usually a single digit) which is bad typographical behav‐
          iour.  Use ‘\~’ to tie the return value to the previous word.

     .Hf  Use this macro to include a (header) file literally.  It first
          prints ‘File:’ followed by the file name, then the contents of
          ⟨file⟩.

                Usage: .Hf ⟨file⟩

          It is neither callable nor parsed.

     .Lk  To be written.

     .Me  Exact usage unknown.  The documentation in the -mdoc source file
          describes it as a macro for “menu entries”.

          Its default width is 6n.

     .Mt  To be written.

     .Ot  Exact usage unknown.  The documentation in the -mdoc source file
          describes it as “old function type (fortran)”.

     .Sm  Activate (toggle) space mode.

                Usage: .Sm [on | off] ...

          If space mode is off, no spaces between macro arguments are
          inserted.  If called without a parameter (or if the next parameter
          is neither ‘on’ nor ‘off’, ‘.Sm’ toggles space mode.

     .Ud  prints

                currently under development.

          It is neither callable nor parsed and takes no arguments.

PREDEFINED STRINGS         top

     The following strings are predefined:

     String   Nroff      Troff   Meaning
     <=       <=         ≤       less equal
     >=       >=         ≥       greater equal
     Rq       ''         ”       right double quote
     Lq       ``         “       left double quote
     ua       ^          ↑       upwards arrow
     aa       ´          ´       acute accent
     ga       `          `       grave accent
     q        "          "       straight double quote
     Pi       pi         π       greek pi
     Ne       !=         ≠       not equal
     Le       <=         ≤       less equal
     Ge       >=         ≥       greater equal
     Lt       <          <       less than
     Gt       >          >       greater than
     Pm       +-         ±       plus minus
     If       infinity   ∞       infinity
     Am       &          &       ampersand
     Na       NaN        NaN     not a number
     Ba       |          |       vertical bar

     The names of the columns Nroff and Troff are a bit misleading; Nroff
     shows the ASCII representation, while Troff gives the best glyph form
     available.  For example, a Unicode enabled TTY-device will have proper
     glyph representations for all strings, whereas the enhancement for a
     Latin1 TTY-device is only the plus-minus sign.

     String names which consist of two characters can be written as ‘\*(xx’;
     string names which consist of one character can be written as ‘\*x’.  A
     generic syntax for a string name of any length is ‘\*[xxx]’ (this is a
     GNU troff(1) extension).

DIAGNOSTICS         top

     The debugging macro ‘.Db’ available in previous versions of -mdoc has
     been removed since GNU troff(1) provides better facilities to check
     parameters; additionally, many error and warning messages have been
     added to this macro package, making it both more robust and verbose.

     The only remaining debugging macro is ‘.Rd’ which yields a register
     dump of all global registers and strings.  A normal user will never
     need it.

FORMATTING WITH GROFF, TROFF, AND NROFF         top

     By default, the package inhibits page breaks, headers, and footers if
     displayed with a TTY device like ‘latin1’ or ‘unicode’, to make the
     manual more efficient for viewing on-line.  This behaviour can be
     changed (e.g. to create a hardcopy of the TTY output) by setting the
     register ‘cR’ to zero while calling groff(1), resulting in multiple
     pages instead of a single, very long page:

           groff -Tlatin1 -rcR=0 -mdoc foo.man > foo.txt

     For double-sided printing, set register ‘D’ to 1:

           groff -Tps -rD1 -mdoc foo.man > foo.ps

     To change the document font size to 11pt or 12pt, set register ‘S’
     accordingly:

           groff -Tdvi -rS11 -mdoc foo.man > foo.dvi

     Register ‘S’ is ignored for TTY devices.

     The line and title length can be changed by setting the registers ‘LL’
     and ‘LT’, respectively:

           groff -Tutf8 -rLL=100n -rLT=100n -mdoc foo.man | less

     If not set, both registers default to 78n for TTY devices and 6.5i oth‐
     erwise.

FILES         top

     doc.tmac          The main manual macro package.
     mdoc.tmac         A wrapper file to call doc.tmac.
     mdoc/doc-common   Common strings, definitions, stuff related typo‐
                       graphic output.
     mdoc/doc-nroff    Definitions used for a TTY output device.
     mdoc/doc-ditroff  Definitions used for all other devices.
     mdoc.local        Local additions and customizations.
     andoc.tmac        Use this file if you don't know whether the -mdoc or
                       the -man package should be used.  Multiple man pages
                       (in either format) can be handled.

SEE ALSO         top

     groff(1), man(1), troff(1), groff_man(7)

BUGS         top

     Section 3f has not been added to the header routines.

     ‘.Nm’ font should be changed in NAME section.

     ‘.Fn’ needs to have a check to prevent splitting up if the line length
     is too short.  Occasionally it separates the last parenthesis, and
     sometimes looks ridiculous if a line is in fill mode.

     The list and display macros do not do any keeps and certainly should be
     able to.

COLOPHON         top

     This page is part of the groff (GNU troff) project.  Information about
     the project can be found at http://www.gnu.org/software/groff/.  If you
     have a bug report for this manual page, see
     http://www.gnu.org/software/groff/.  This page was obtained from the
     tarball groff-1.22.3.tar.gz fetched from ftp://ftp.gnu.org/gnu/groff/
     on 2016-08-07.  If you discover any rendering problems in this HTML
     version of the page, or you believe there is a better or more up-to-
     date source for the page, or you have corrections or improvements to
     the information in this COLOPHON (which is not part of the original
     manual page), send a mail to man-pages@man7.org

BSD                           November 2, 2010                           BSD