MDOC(7) Miscellaneous Information Manual MDOC(7)

mdoc - semantic markup language for formatting manual pages

The mdoc language supports authoring of manual pages for the man(1) utility by allowing semantic annotations of words, phrases, page sections and complete manual pages. Such annotations are used by formatting tools to achieve a uniform presentation across all manuals written in mdoc, and to support hyperlinking if supported by the output medium.

This reference document describes the structure of manual pages and the syntax and usage of the mdoc language. The reference implementation of a parsing and formatting tool is mandoc(1); the COMPATIBILITY section describes compatibility with other implementations.

In an mdoc document, lines beginning with the control character ‘.’ are called “macro lines”. The first word is the macro name. It consists of two or three letters. Most macro names begin with a capital letter. For a list of available macros, see MACRO OVERVIEW. The words following the macro name are arguments to the macro, optionally including the names of other, callable macros; see MACRO SYNTAX for details.

Lines not beginning with the control character are called “text lines”. They provide free-form text to be printed; the formatting of the text depends on the respective processing context:





.Sh Macro lines change control state.
Text lines are interpreted within the current state.






Many aspects of the basic syntax of the mdoc language are
    based on the roff(7) language; see the LANGUAGE SYNTAX and MACRO
    SYNTAX sections in the roff(7) manual for details, in particular
    regarding comments, escape sequences, whitespace, and quoting. However,
    using roff(7) requests in mdoc documents is discouraged; mandoc(1)
    supports some of them merely for backward compatibility.








A well-formed mdoc document consists of a document prologue
    followed by one or more sections.


The prologue, which consists of the Dd, Dt, and
    Os macros in that order, is required for every document.


The first section (sections are denoted by Sh) must be the
    NAME section, consisting of at least one Nm followed by
  Nd.


Following that, convention dictates specifying at least the
    SYNOPSIS and DESCRIPTION sections, although this varies
    between manual sections.


The following is a well-formed skeleton mdoc file for a
    utility "progname":






.Dd $Mdocdate$
.Dt PROGNAME section
.Os
.Sh NAME
.Nm progname
.Nd one line about what it does
.\" .Sh LIBRARY
.\" For sections 2, 3, and 9 only.
.\" Not used in OpenBSD.
.Sh SYNOPSIS
.Nm progname
.Op Fl options
.Ar
.Sh DESCRIPTION
The
.Nm
utility processes files ...
.\" .Sh CONTEXT
.\" For section 9 functions only.
.\" .Sh IMPLEMENTATION NOTES
.\" Not used in OpenBSD.
.\" .Sh RETURN VALUES
.\" For sections 2, 3, and 9 function return values only.
.\" .Sh ENVIRONMENT
.\" For sections 1, 6, 7, and 8 only.
.\" .Sh FILES
.\" .Sh EXIT STATUS
.\" For sections 1, 6, and 8 only.
.\" .Sh EXAMPLES
.\" .Sh DIAGNOSTICS
.\" For sections 1, 4, 6, 7, 8, and 9 printf/stderr messages only.
.\" .Sh ERRORS
.\" For sections 2, 3, 4, and 9 errno settings only.
.\" .Sh SEE ALSO
.\" .Xr foobar 1
.\" .Sh STANDARDS
.\" .Sh HISTORY
.\" .Sh AUTHORS
.\" .Sh CAVEATS
.\" .Sh BUGS
.\" .Sh SECURITY CONSIDERATIONS
.\" Not used in OpenBSD.






The sections in an mdoc document are conventionally ordered
    as they appear above. Sections should be composed as follows:




NAME
  

  The name(s) and a one line description of the documented material. The syntax
    for this as follows:






.Nm name0 ,
.Nm name1 ,
.Nm name2
.Nd a one line description






Multiple ‘Nm’ names should be separated by
  commas.


The Nm macro(s) must precede the Nd macro.


See Nm and Nd.


LIBRARY
  

  The name of the library containing the documented material, which is assumed
    to be a function in a section 2, 3, or 9 manual. The syntax for this is as
    follows:






.Lb libarm






See Lb.


SYNOPSIS
  

  Documents the utility invocation syntax, function call syntax, or device
    configuration.


For the first, utilities (sections 1, 6, and 8), this is generally
    structured as follows:






.Nm bar
.Op Fl v
.Op Fl o Ar file
.Op Ar
.Nm foo
.Op Fl v
.Op Fl o Ar file
.Op Ar






Commands should be ordered alphabetically.


For the second, function calls (sections 2, 3, 9):






.In header.h
.Vt extern const char *global;
.Ft "char *"
.Fn foo "const char *src"
.Ft "char *"
.Fn bar "const char *src"






Ordering of In, Vt, Fn, and Fo macros
    should follow C header-file conventions.


And for the third, configurations (section 4):






.Cd "it* at isa? port 0x2e"
.Cd "it* at isa? port 0x4e"






Manuals not in these sections generally don't need a
    SYNOPSIS.


Some macros are displayed differently in the SYNOPSIS
    section, particularly Nm, Cd, Fd, Fn, Fo,
    In, Vt, and Ft. All of these macros are output on their
    own line. If two such dissimilar macros are pairwise invoked (except for
    Ft before Fo or Fn), they are separated by a vertical
    space, unless in the case of Fo, Fn, and Ft, which are
    always separated by vertical space.


When text and macros following an Nm macro starting an
    input line span multiple output lines, all output lines but the first will
    be indented to align with the text immediately following the Nm
    macro, up to the next Nm, Sh, or Ss macro or the end of
    an enclosing block, whichever comes first.


DESCRIPTION
  

  This begins with an expansion of the brief, one line description in
    NAME:






The
.Nm
utility does this, that, and the other.






It usually follows with a breakdown of the options (if documenting
    a command), such as:






The options are as follows:
.Bl -tag -width Ds
.It Fl v
Print verbose information.
.El






List the options in alphabetical order, uppercase before lowercase
    for each letter and with no regard to whether an option takes an argument.
    Put digits in ascending order before all letter options.


Manuals not documenting a command won't include the above
    fragment.


Since the DESCRIPTION section usually contains most of the
    text of a manual, longer manuals often use the Ss macro to form
    subsections. In very long manuals, the DESCRIPTION may be split into
    multiple sections, each started by an Sh macro followed by a
    non-standard section name, and each having several subsections, like in the
    present mdoc manual.


CONTEXT
  

  This section lists the contexts in which functions can be called in section 9.
    The contexts are autoconf, process, or interrupt.


IMPLEMENTATION NOTES
  

  Implementation-specific notes should be kept here. This is useful when
    implementing standard functions that may have side effects or notable
    algorithmic implications.


RETURN VALUES
  

  This section documents the return values of functions in sections 2, 3, and
  9.


See Rv.


ENVIRONMENT
  

  Lists the environment variables used by the utility, and explains the syntax
    and semantics of their values. The environ(7) manual provides examples of
    typical content and formatting.


See Ev.


FILES
  

  Documents files used. It's helpful to document both the file name and a short
    description of how the file is used (created, modified, etc.).


See Pa.


EXIT STATUS
  

  This section documents the command exit status for section 1, 6, and 8
    utilities. Historically, this information was described in
    DIAGNOSTICS, a practise that is now discouraged.


See Ex.


EXAMPLES
  

  Example usages. This often contains snippets of well-formed, well-tested
    invocations. Make sure that examples work properly!


DIAGNOSTICS
  

  Documents error messages. In section 4 and 9 manuals, these are usually
    messages printed by the kernel to the console and to the kernel log. In
    section 1, 6, 7, and 8, these are usually messages printed by userland
    programs to the standard error output.


Historically, this section was used in place of EXIT STATUS
    for manuals in sections 1, 6, and 8; however, this practise is
  discouraged.


See Bl -diag.


ERRORS
  

  Documents errno(2) settings in sections 2, 3, 4, and 9.


See Er.


SEE ALSO
  

  References other manuals with related topics. This section should exist for
    most manuals. Cross-references should conventionally be ordered first by
    section, then alphabetically (ignoring case).


References to other documentation concerning the topic of the
    manual page, for example authoritative books or journal articles, may also
    be provided in this section.


See Rs and Xr.


STANDARDS
  

  References any standards implemented or used. If not adhering to any
    standards, the HISTORY section should be used instead.


See St.


HISTORY
  

  A brief history of the subject, including where it was first implemented, and
    when it was ported to or reimplemented for the operating system at hand.


AUTHORS
  

  Credits to the person or persons who wrote the code and/or documentation.
    Authors should generally be noted by both name and email address.


See An.


CAVEATS
  

  Common misuses and misunderstandings should be explained in this section.


BUGS
  

  Known bugs, limitations, and work-arounds should be described in this
  section.


SECURITY CONSIDERATIONS
  

  Documents any security precautions that operators should consider.










This overview is sorted such that macros of similar purpose are
    listed together, to help find the best macro for any given purpose.
    Deprecated macros are not included in the overview, but can be found below
    in the alphabetical MACRO REFERENCE.







  

  

  

    Dd
    document date: $Mdocdate$ | month day, year
  

  

  

  

    Dt
    document title: TITLE section [arch]
  

  

  

  

    Os
    operating system version: [system [version]]
  

  

  

  

    Nm
    document name (one argument)
  

  

  

  

    Nd
    document description (one line)
  











  

  

  

    Sh
    section header (one line)
  

  

  

  

    Ss
    subsection header (one line)
  

  

  

  

    Sx
    internal cross reference to a section or subsection
  

  

  

  

    Xr
    cross reference to another manual page: name section
  

  

  

  

    Tg
    tag the definition of a term (<= 1 arguments)
  

  

  

  

    Pp
    start a text paragraph (no arguments)
  











  

  

  

    Bd, Ed
    display block:
  

  

    -type
  

  

    [-offset width]
  

  

    [-compact]
  

  

  

  

    D1
    indented display (one line)
  

  

  

  

    Dl
    indented literal display (one line)
  

  

  

  

    Ql
    in-line literal display: ‘text’
  

  

  

  

    Bl, El
    list block:
  

  

    -type
  

  

    [-width val]
  

  

    [-offset val]
  

  

    [-compact]
  

  

  

  

    It
    list item (syntax depends on -type)
  

  

  

  

    Ta
    table cell separator in Bl -column lists
  

  

  

  

    Rs, %*, Re
    bibliographic block (references)
  











  

  

  

    Pf
    prefix, no following horizontal space (one argument)
  

  

  

  

    Ns
    roman font, no preceding horizontal space (no arguments)
  

  

  

  

    Ap
    apostrophe without surrounding whitespace (no arguments)
  

  

  

  

    Sm
    switch horizontal spacing mode: [on | off]
  

  

  

  

    Bk, Ek
    keep block: -words
  











  

  

  

    Nm
    start a SYNOPSIS block with the name of a utility
  

  

  

  

    Fl
    command line options (flags) (>=0 arguments)
  

  

  

  

    Cm
    command modifier (>0 arguments)
  

  

  

  

    Ar
    command arguments (>=0 arguments)
  

  

  

  

    Op, Oo, Oc
    optional syntax elements (enclosure)
  

  

  

  

    Ic
    internal or interactive command (>0 arguments)
  

  

  

  

    Ev
    environmental variable (>0 arguments)
  

  

  

  

    Pa
    file system path (>=0 arguments)
  











  

  

  

    Lb
    function library (one argument)
  

  

  

  

    In
    include file (one argument)
  

  

  

  

    Fd
    other preprocessor directive (>0 arguments)
  

  

  

  

    Ft
    function type (>0 arguments)
  

  

  

  

    Fo, Fc
    function block: funcname
  

  

  

  

    Fn
    function name: funcname [argument ...]
  

  

  

  

    Fa
    function argument (>0 arguments)
  

  

  

  

    Vt
    variable type (>0 arguments)
  

  

  

  

    Va
    variable name (>0 arguments)
  

  

  

  

    Dv
    defined variable or preprocessor constant (>0 arguments)
  

  

  

  

    Er
    error constant (>0 arguments)
  

  

  

  

    Ev
    environmental variable (>0 arguments)
  











  

  

  

    An
    author name (>0 arguments)
  

  

  

  

    Lk
    hyperlink: uri [display_name]
  

  

  

  

    Mt
    “mailto” hyperlink: localpart@domain
  

  

  

  

    Cd
    kernel configuration declaration (>0 arguments)
  

  

  

  

    Ad
    memory address (>0 arguments)
  

  

  

  

    Ms
    mathematical symbol (>0 arguments)
  











  

  

  

    Em
    italic font or underline (emphasis) (>0 arguments)
  

  

  

  

    Sy
    boldface font (symbolic) (>0 arguments)
  

  

  

  

    No
    return to roman font (normal) (>0 arguments)
  

  

  

  

    Bf, Ef
    font block: -type | Em | Li | Sy
  











  

  

  

    Dq, Do, Dc
    enclose in typographic double quotes: “text”
  

  

  

  

    Qq, Qo, Qc
    enclose in typewriter double quotes: "text"
  

  

  

  

    Sq, So, Sc
    enclose in single quotes: ‘text’
  

  

  

  

    Pq, Po, Pc
    enclose in parentheses: (text)
  

  

  

  

    Bq, Bo, Bc
    enclose in square brackets: [text]
  

  

  

  

    Brq, Bro, Brc
    enclose in curly braces: {text}
  

  

  

  

    Aq, Ao, Ac
    enclose in angle brackets: ⟨text⟩
  

  

  

  

    Eo, Ec
    generic enclosure
  











  

  

  

    Ex -std
    standard command exit values: [utility ...]
  

  

  

  

    Rv -std
    standard function return values: [function ...]
  

  

  

  

    St
    reference to a standards document (one argument)
  

  

  

  

    At
    AT&T UNIX
  

  

  

  

    Bx
    BSD
  

  

  

  

    Bsx
    BSD/OS
  

  

  

  

    Nx
    NetBSD
  

  

  

  

    Fx
    FreeBSD
  

  

  

  

    Ox
    OpenBSD
  

  

  

  

    Dx
    DragonFly
  












This section is a canonical reference of all macros, arranged
    alphabetically. For the scoping of individual macros, see MACRO
    SYNTAX.



  
%A first_name ... last_name

  
Author name of an Rs block. Multiple authors should each be
      accorded their own %A line. Author names should be ordered with
      full or abbreviated forename(s) first, then full surname.

  
%B title

  
Book title of an Rs block. This macro may also be used in a
      non-bibliographic context when referring to book titles.

  
%C location

  
Publication city or location of an Rs block.

  
%D [month day,] year

  
Publication date of an Rs block. Provide the full English name of
      the month and all four digits of the year.

  
%I name

  
Publisher or issuer name of an Rs block.

  
%J name

  
Journal name of an Rs block.

  
%N number

  
Issue number (usually for journals) of an Rs block.

  
%O line

  
Optional information of an Rs block.

  
%P number

  
Book or journal page number of an Rs block. Conventionally, the
      argument starts with ‘p.’ for a single page or
      ‘pp.’ for a range of pages, for example:
    

  




.%P pp. 42\(en47



  
%Q name

  
Institutional author (school, government, etc.) of an Rs block.
      Multiple institutional authors should each be accorded their own %Q
      line.

  
%R name

  
Technical report name of an Rs block.

  
%T title

  
Article title of an Rs block. This macro may also be used in a
      non-bibliographical context when referring to article titles.

  
%U protocol://path

  
URI of reference document.

  
%V number

  
Volume number of an Rs block.

  

  

    

    Close an Ao block. Does not have any tail arguments.

  
  
Memory address. Do not use this for postal addresses.
    
Examples:

  




.Ad [0,$]




.Ad 0x00000000





  

  
Author name. Can be used both for the authors of the program, function, or
      driver documented in the manual, or for the authors of the manual itself.
      Requires either the name of an author or one of the following arguments:
    

  







  

  
Start a new output line before each subsequent invocation of
    An.

  

  
The opposite of -split.








The default is -nosplit. The effect of selecting either of
    the -split modes ends at the beginning of the AUTHORS section.
    In the AUTHORS section, the default is -nosplit for the first
    author listing and -split for all other author listings.


Examples:


.An -nosplit


.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv





  

  
Begin a block enclosed by angle brackets. Does not have any head
      arguments. This macro is almost never useful. See Aq for more
      details.

  

  

    

    Inserts an apostrophe without any surrounding whitespace. This is generally
      used as a grammatical device when referring to the verb form of a
      function.
    
Examples:

  




.Fn execve Ap d



  

  
Enclose the rest of the input line in angle brackets. The only important
      use case is for email addresses. See Mt for an example.
    
Occasionally, it is used for names of characters and keys, for
        example:

    
    

  






Press the
.Aq escape
key to ...








For URIs, use Lk instead, and In for
    “#include” directives. Never wrap Ar in Aq.


Since Aq usually renders with non-ASCII characters in
    non-ASCII output modes, do not use it where the ASCII characters
    ‘<’ and ‘>’ are required as syntax
    elements. Instead, use these characters directly in such cases, combining
    them with the macros Pf, Ns, or Eo as needed.


See also Ao.





  

  
Command arguments. If an argument is not provided, the string “file
      ...” is used as a default.
    
Examples:

  




.Fl o Ar file




.Ar


.Ar arg1 , arg2 .


The arguments to the Ar macro are names and placeholders
    for command arguments; for fixed strings to be passed verbatim as arguments,
    use Fl or Cm.





  

  
Formats an AT&T UNIX version. Accepts one optional argument:
    

  







  

  
A version of AT&T UNIX.

  

  
AT&T System III UNIX.

  

  
A version of AT&T System V UNIX.








Note that these arguments do not begin with a hyphen.


Examples:


.At


.At III


.At V.1


See also Bsx, Bx, Dx, Fx, Nx,
    and Ox.





  

  

    

    Close a Bo block. Does not have any tail arguments.

  

  
Begin a display block. Display blocks are used to select a different
      indentation and justification than the one used by the surrounding text.
      They may contain both macro lines and text lines. By default, a display
      block is preceded by a vertical space.
    
The type must be one of the following:

  







  

  
Produce one output line from each input line, and center-justify each
      line. Using this display type is not recommended; many mdoc
      implementations render it poorly.

  

  
Change the positions of line breaks to fill each line, and left- and
      right-justify the resulting block.

  

  
Produce one output line from each input line, and do not justify the block
      at all. Preserve white space as it appears in the input. Always use a
      constant-width font. Use this for displaying source code.

  

  
Change the positions of line breaks to fill each line, and left-justify
      the resulting block.

  

  
The same as -literal, but using the same font as for normal text,
      which is a variable width font if supported by the output device.








The type must be provided first. Additional arguments may
    follow:





  

  

    

    Indent the display by the width, which may be one of the
    following:




One of the pre-defined strings indent, the width of a
    standard indentation (six constant width characters); indent-two,
    twice indent; left, which has no effect; right, which
    justifies to the right margin; or center, which aligns around an
    imagined center axis.


A macro invocation, which selects a predefined width associated
    with that macro. The most popular is the imaginary macro Ds, which
    resolves to 6n.


A scaling width as described in roff(7).


An arbitrary string, which indents by the length of this
  string.






When the argument is missing, -offset is ignored.





  

  
Do not assert vertical space before the display.






Examples:






.Bd -literal -offset indent -compact
   Hello       world.
.Ed






See also D1 and Dl.





  

  
Change the font mode for a scoped block of text. The -emphasis and
      Em argument are equivalent, as are -symbolic and Sy,
      and -literal and Li. Without an argument, this macro does
      nothing. The font mode continues until broken by a new font mode in a
      nested scope or Ef is encountered.
    
See also Li, Ef, Em, and Sy.

  

  

  
For each macro, keep its output together on the same output line, until
      the end of the macro or the end of the input line is reached, whichever
      comes first. Line breaks in text lines are unaffected.
    
The -words argument is required; additional arguments
        are ignored.

    
The following example will not break within each Op
        macro line:

    
    

  






.Bk -words
.Op Fl f Ar flags
.Op Fl o Ar output
.Ek








Be careful in using over-long lines within a keep block! Doing so
    will clobber the right margin.





  

  

    

    -type [-width val] [-offset val]
      [-compact] [col ...] Begin a list. Lists consist of items
      specified using the It macro, containing a head or a body or both.
    
The list type is mandatory and must be specified first.
        The -width and -offset arguments accept macro names as
        described for Bd -offset, scaling widths as described in
        roff(7), or use the length of the given string. The -offset is a
        global indentation for the whole list, affecting both item heads and
        bodies. For those list types supporting it, the -width argument
        requests an additional indentation of item bodies, to be added to the
        -offset. Unless the -compact argument is specified, list
        entries are separated by vertical space.

    
A list must specify one of the following list types:

  







  

  
No item heads can be specified, but a bullet will be printed at the head
      of each item. Item bodies start on the same output line as the bullet and
      are indented according to the -width argument.

  

  
A columnated list. The -width argument has no effect; instead, the
      string length of each argument specifies the width of one column. If the
      first line of the body of a -column list is not an It macro
      line, It contexts spanning one input line each are implied until an
      It macro line is encountered, at which point items start being
      interpreted as described in the It documentation.

  

  
Like -bullet, except that dashes are used in place of bullets.

  

  
Like -inset, except that item heads are not parsed for macro
      invocations. Most often used in the DIAGNOSTICS section with error
      constants in the item heads.

  

  
A numbered list. No item heads can be specified. Formatted like
      -bullet, except that cardinal numbers are used in place of bullets,
      starting at 1.

  

  
Like -tag, except that the first lines of item bodies are not
      indented, but follow the item heads like in -inset lists.

  

  
Synonym for -dash.

  

  
Item bodies follow items heads on the same line, using normal inter-word
      spacing. Bodies are not indented, and the -width argument is
      ignored.

  

  
No item heads can be specified, and none are printed. Bodies are not
      indented, and the -width argument is ignored.

  

  
Item bodies start on the line following item heads and are not indented.
      The -width argument is ignored.

  

  
Item bodies are indented according to the -width argument. When an
      item head fits inside the indentation, the item body follows this head on
      the same output line. Otherwise, the body starts on the output line
      following the head.








Lists may be nested within lists and displays. Nesting of
    -column and -enum lists may not be portable.


See also El and It.





  

  
Begin a block enclosed by square brackets. Does not have any head
      arguments.
    
Examples:

  






.Bo 1 ,
.Dv BUFSIZ Bc








See also Bq.





  

  
Encloses its arguments in square brackets.
    
Examples:

  




.Bq 1, Dv BUFSIZ




Remarks: this macro is sometimes abused to emulate optional
    arguments for commands; the correct macros to use for this purpose are
    Op, Oo, and Oc.


See also Bo.





  

  
Close a Bro block. Does not have any tail arguments.

  

  
Begin a block enclosed by curly braces. Does not have any head arguments.
    
Examples:

  






.Bro 1 , ... ,
.Va n Brc








See also Brq.





  

  
Encloses its arguments in curly braces.
    
Examples:

  




.Brq 1, ..., Va n




See also Bro.





  

  
Format the BSD/OS version provided as an argument, or a default value if
      no argument is provided.
    
Examples:

  




.Bsx 1.0




.Bsx


See also At, Bx, Dx, Fx, Nx,
    and Ox.





  

  

    

    Supported only for compatibility, do not use this in new manuals. Prints
      “is currently in beta test.”

  

  
Format the BSD version provided as an argument, or a default value if no
      argument is provided.
    
Examples:

  




.Bx 4.3 Tahoe




.Bx 4.4


.Bx


See also At, Bsx, Dx, Fx, Nx,
    and Ox.





  

  
Kernel configuration declaration. This denotes strings accepted by
      config(8). It is most often used in section 4 manual pages.
    
Examples:

  




.Cd device le0 at scode?




Remarks: this macro is commonly abused by using quoted
    literals to retain whitespace and align consecutive Cd declarations.
    This practise is discouraged.





  

  
Command modifiers. Typically used for fixed strings passed as arguments to
      interactive commands, to commands in interpreted scripts, or to
      configuration file directives, unless Fl is more appropriate.
    
Examples:

  




.Nm mt Fl f Ar device Cm rewind




.Nm ps Fl o Cm pid , Ns Cm command


.Nm dd Cm if= Ns Ar file1 Cm of= Ns Ar file2


.Ic set Fl o Cm vi


.Ic lookup Cm file bind


.Ic permit Ar identity Op Cm as Ar target





  

  
One-line indented display. This is formatted by the default rules and is
      useful for simple indented statements. It is followed by a newline.
    
Examples:

  




.D1 Fl abcdefgh




See also Bd and Dl.





  

  

    

    This macro is obsolete. No replacement is needed. It is ignored by mandoc(1)
      and groff including its arguments. It was formerly used to toggle a
      debugging mode.

  

  

    

    Close a Do block. Does not have any tail arguments.

  

  
Document date for display in the page footer, by convention the date of
      the last change. This is the mandatory first macro of any mdoc
      manual.
    
The month is the full English month name, the
        day is an integer number, and the year is the full
        four-digit year.

    
Other arguments are not portable; the mandoc(1) utility
        handles them as follows:

  







  
-

  
To have the date automatically filled in by the OpenBSD version of cvs(1),
      the special string “$Mdocdate$” can be given as an
    argument.

  
-

  
The traditional, purely numeric man(7) format
      year–month–day is accepted, too.

  
-

  
If a date string cannot be parsed, it is used verbatim.

  
-

  
If no date string is given, the current date is used.








Examples:


.Dd $Mdocdate$


.Dd $Mdocdate: July 2 2018$


.Dd July 2, 2018


See also Dt and Os.





  

  
One-line indented display. This is formatted as literal text and is useful
      for commands and invocations. It is followed by a newline.
    
Examples:

  




.Dl % mandoc mdoc.7 \(ba less




See also Ql, Bd -literal, and D1.





  

  
Begin a block enclosed by double quotes. Does not have any head arguments.
    
Examples:

  






.Do
April is the cruellest month
.Dc
\(em T.S. Eliot








See also Dq.





  

  
Encloses its arguments in “typographic” double-quotes.
    
Examples:

  






.Dq April is the cruellest month
\(em T.S. Eliot








See also Qq, Sq, and Do.





  

  
Document title for display in the page header. This is the mandatory
      second macro of any mdoc file.
    
Its arguments are as follows:

  







  

  
The document's title (name), defaulting to “UNTITLED” if
      unspecified. To achieve a uniform appearance of page header lines, it
      should by convention be all caps.

  

  
The manual section. This may be one of 1 (General Commands),
      2 (System Calls), 3 (Library Functions), 3p (Perl
      Library), 4 (Device Drivers), 5 (File Formats), 6
      (Games), 7 (Miscellaneous Information), 8 (System Manager's
      Manual), or 9 (Kernel Developer's Manual). It should correspond to
      the manual's filename suffix and defaults to the empty string if
      unspecified.

  

  
This specifies the machine architecture a manual page applies to, where
      relevant, for example alpha, amd64, i386, or
      sparc64. The list of valid architectures varies by operating
      system.








Examples:


.Dt FOO 1


.Dt FOO 9 i386


See also Dd and Os.





  

  
Defined variables such as preprocessor constants, constant symbols,
      enumeration values, and so on.
    
Examples:

  




.Dv NULL




.Dv BUFSIZ


.Dv STDOUT_FILENO


See also Er and Ev for special-purpose constants,
    Va for variable symbols, and Fd for listing preprocessor
    variable definitions in the SYNOPSIS.





  

  
Format the DragonFly version provided as an argument, or a default value
      if no argument is provided.
    
Examples:

  




.Dx 2.4.1




.Dx


See also At, Bsx, Bx, Fx, Nx,
    and Ox.





  

  
Close a scope started by Eo.
    
The closing_delimiter argument is used as the enclosure
        tail, for example, specifying \(rq will emulate Dc.

  

  

  

    

    End a display context started by Bd.

  

  

    

    End a font mode context started by Bf.

  

  

    

    End a keep context started by Bk.

  

  

    

    End a list context started by Bl. See also It.

  

  
Request an italic font. If the output device does not provide that,
      underline.
    
This is most often used for stress emphasis (not to be
        confused with importance, see Sy). In the rare cases where none
        of the semantic markup macros fit, it can also be used for technical
        terms and placeholders, except that for syntax elements, Sy and
        Ar are preferred, respectively.

    
Examples:

  






Selected lines are those
.Em not
matching any of the specified patterns.
Some of the functions use a
.Em hold space
to save the pattern space for subsequent retrieval.








See also No, Ql, and Sy.





  

  
This macro is obsolete. Use Eo or any of the other enclosure
      macros.
    
It encloses its argument in the delimiters specified by the
        last Es macro.

  

  

  
An arbitrary enclosure. The opening_delimiter argument is used as
      the enclosure head, for example, specifying \(lq will emulate
    Do.

  

  
Error constants for definitions of the errno libc global variable.
      This is most often used in section 2 and 3 manual pages.
    
Examples:

  




.Er EPERM




.Er ENOENT


See also Dv for general constants.





  

  
This macro is obsolete. Use Eo or any of the other enclosure
      macros.
    
It takes two arguments, defining the delimiters to be used by
        subsequent En macros.

  

  

  
Environmental variables such as those specified in environ(7).
    
Examples:

  




.Ev DISPLAY




.Ev PATH


See also Dv for general constants.





  

  
Insert a standard sentence regarding command exit values of 0 on success
      and >0 on failure. This is most often used in section 1, 6, and 8
      manual pages.
    
If utility is not specified, the document's name set by
        Nm is used. Multiple utility arguments are treated as
        separate utilities.

    
See also Rv.

  

  

  
Function argument or parameter. Each argument may be a name and a type
      (recommended for the SYNOPSIS section), a name alone (for function
      invocations), or a type alone (for function prototypes). If both a type
      and a name are given or if the type consists of multiple words, all words
      belonging to the same function argument have to be given in a single
      argument to the Fa macro.
    
This macro is also used to specify the field name of a
        structure.

    
Most often, the Fa macro is used in the SYNOPSIS
        within Fo blocks when documenting multi-line function prototypes.
        If invoked with multiple arguments, the arguments are separated by a
        comma. Furthermore, if the following macro is another Fa, the
        last argument will also have a trailing comma.

    
Examples:

  




.Fa "const char *p"




.Fa "int a" "int b" "int
  c"


.Fa "char *" size_t


See also Fo.





  

  

    

    End a function context started by Fo.

  

  
Preprocessor directive, in particular for listing it in the
      SYNOPSIS. Historically, it was also used to document include files.
      The latter usage has been deprecated in favour of In.
    
Examples:

  




.Fd #define sa_handler __sigaction_u.__sa_handler




.Fd #define SIO_MAXNFDS


.Fd #ifdef FS_DEBUG


.Ft void


.Fn dbg_open "const char *"


.Fd #endif


See also MANUAL STRUCTURE, In, and Dv.





  

  
Command-line flag or option. Used when listing arguments to command-line
      utilities. For each argument, prints an ASCII hyphen-minus character
      ‘-’, immediately followed by the argument. If no arguments
      are provided, a hyphen-minus is printed followed by a space. If the
      argument is a macro, a hyphen-minus is prefixed to the subsequent macro
      output.
    
Examples:

  




.Nm du Op Fl H | L | P




.Nm ls Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux


.Nm route Cm add Fl inet Ar destination gateway


.Nm locate.updatedb Op Fl \-fcodes Ns = Ns Ar
  dbfile


.Nm aucat Fl o Fl


.Nm kill Fl Ar signal_number


For GNU-sytle long options, escaping the additional hyphen-minus
    is not strictly required, but may be safer with future versions of GNU
    troff; see mandoc_char(7) for details.


See also Cm.





  

  
A function name.
    
Function arguments are surrounded in parenthesis and are
        delimited by commas. If no arguments are specified, blank parenthesis
        are output. In the SYNOPSIS section, this macro starts a new
        output line, and a blank line is automatically inserted between function
        definitions.

    
Examples:

  




.Fn "int funcname" "int arg0"
  "int arg1"




.Fn funcname "int arg0"


.Fn funcname arg0






.Ft functype
.Fn funcname






When referring to a function documented in another manual page,
    use Xr instead. See also MANUAL STRUCTURE, Fo, and
    Ft.





  

  
Begin a function block. This is a multi-line version of Fn.
    
Invocations usually occur in the following context:

    

  







...







A Fo scope is closed by Fc.


See also MANUAL STRUCTURE, Fa, Fc, and
    Ft.





  

  
This macro is obsolete. No replacement markup is needed.
    
It was used to show numerical function return values in an
        italic font.

  

  

  
A function type.
    
In the SYNOPSIS section, a new output line is started
        after this macro.

    
Examples:

  




.Ft int






.Ft functype
.Fn funcname






See also MANUAL STRUCTURE, Fn, and Fo.





  

  
Format the FreeBSD version provided as an argument, or a default value if
      no argument is provided.
    
Examples:

  




.Fx 7.1




.Fx


See also At, Bsx, Bx, Dx, Nx,
    and Ox.





  

  
This macro is not implemented in mandoc(1). It was used to include the
      contents of a (header) file literally.

  

  
Internal or interactive command, or configuration instruction in a
      configuration file. See also Cm.
    
Examples:

  




.Ic :wq




.Ic hash


.Ic alias


Note that using Ql, Dl, or Bd -literal
    is preferred for displaying code samples; the Ic macro is used when
    referring to an individual command name.





  

  
The name of an include file. This macro is most often used in section 2,
      3, and 9 manual pages.
    
When invoked as the first macro on an input line in the
        SYNOPSIS section, the argument is displayed in angle brackets and
        preceded by "#include", and a blank line is inserted in front
        if there is a preceding function declaration. In other sections, it only
        encloses its argument in angle brackets and causes no line break.

    
Examples:

  




.In sys/types.h




See also MANUAL STRUCTURE.





  

  
A list item. The syntax of this macro depends on the list type.
    
Lists of type -hang, -ohang, -inset, and
        -diag have the following syntax:

    

  








Lists of type -bullet, -dash, -enum,
    -hyphen and -item have the following syntax:






with subsequent lines interpreted within the scope of the
    It until either a closing El or another It.


The -tag list has the following syntax:






Subsequent lines are interpreted as with -bullet and
    family. The line arguments correspond to the list's left-hand side; body
    arguments correspond to the list's contents.


The -column list is the most complicated. Its syntax is as
    follows:








The arguments consist of one or more lines of text and macros
    representing a complete table line. Cells within the line are delimited by
    the special Ta block macro or by literal tab characters.


Using literal tabs is strongly discouraged because they are very
    hard to use correctly and mdoc code using them is very hard to read.
    In particular, a blank character is syntactically significant before and
    after the literal tab character. If a word precedes or follows the tab
    without an intervening blank, that word is never interpreted as a macro
    call, but always output literally.


The tab cell delimiter may only be used within the It line
    itself; on following lines, only the Ta macro can be used to delimit
    cells, and portability requires that Ta is called by other macros:
    some parsers do not recognize it when it appears as the first macro on a
    line.


Note that quoted strings may span tab-delimited cells on an
    It line. For example,




.It "col1 , <TAB> col2 ," ;


will preserve the whitespace before both commas, but not the
    whitespace before the semicolon.


See also Bl.





  

  
Specify a library.
    
The name parameter may be a system library, such as
        z or pam, in which case a small library description is
        printed next to the linker invocation; or a custom library, in which
        case the library name is printed in quotes. This is most commonly used
        in the SYNOPSIS section as described in MANUAL
      STRUCTURE.

    
Examples:

  




.Lb libz




.Lb libmandoc





  

  
Request a typewriter (literal) font. Deprecated because on terminal output
      devices, this is usually indistinguishable from normal text. For literal
      displays, use Ql (in-line), Dl (single line), or Bd
      -literal (multi-line) instead.

  

  
Format a hyperlink.
    
Examples:

  




.Lk https://bsd.lv "The BSD.lv Project"




.Lk https://bsd.lv


See also Mt.





  

  

    

    Deprecated synonym for Pp.

  

  
Display a mathematical symbol.
    
Examples:

  




.Ms sigma




.Ms aleph





  

  
Format a “mailto:” hyperlink.
    
Examples:

  




.Mt discuss@manpages.bsd.lv




.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv





  

  
A one line description of the manual's content. This is the mandatory last
      macro of the NAME section and not appropriate for other sections.
    
Examples:

  




.Nd mdoc language reference




.Nd format and display UNIX manuals


The Nd macro technically accepts child macros and
    terminates with a subsequent Sh invocation. Do not assume this
    behaviour: some whatis(1) database generators are not smart enough to parse
    more than the line arguments and will display macros verbatim.


See also Nm.





  

  
The name of the manual page, or — in particular in section 1, 6,
      and 8 pages — of an additional command or feature documented in the
      manual page. When first invoked, the Nm macro expects a single
      argument, the name of the manual page. Usually, the first invocation
      happens in the NAME section of the page. The specified name will be
      remembered and used whenever the macro is called again without arguments
      later in the page. The Nm macro uses Block full-implicit
      semantics when invoked as the first macro on an input line in the
      SYNOPSIS section; otherwise, it uses ordinary In-line
      semantics.
    
Examples:

    
    

  






.Sh SYNOPSIS
.Nm cat
.Op Fl benstuv
.Op Ar








In the SYNOPSIS of section 2, 3 and 9 manual pages, use the
    Fn macro rather than Nm to mark up the name of the manual
    page.





  

  
Normal text. Closes the scope of any preceding in-line macro. When used
      after physical formatting macros like Em or Sy, switches
      back to the standard font face and weight. Can also be used to embed plain
      text strings in macro lines using semantic annotation macros.
    
Examples:

  




.Em italic , Sy bold , No and roman








.Sm off
.Cm :C No / Ar pattern No / Ar replacement No /
.Sm on






See also Em, Ql, and Sy.





  

  

    

    Suppress a space between the output of the preceding macro and the following
      text or macro. Following invocation, input is interpreted as normal text
      just like after an No macro.
    
This has no effect when invoked at the start of a macro
      line.

    
Examples:

  




.Ar name Ns = Ns Ar value




.Cm :M Ns Ar pattern


.Fl o Ns Ar output


See also No and Sm.





  

  
Format the NetBSD version provided as an argument, or a default value if
      no argument is provided.
    
Examples:

  




.Nx 5.01




.Nx


See also At, Bsx, Bx, Dx, Fx,
    and Ox.





  

  

    

    Close multi-line Oo context.

  

  
Multi-line version of Op.
    
Examples:

  






.Oo
.Op Fl flag Ns Ar value
.Oc







  

  
Optional part of a command line. Prints the argument(s) in brackets. This
      is most often used in the SYNOPSIS section of section 1 and 8
      manual pages.
    
Examples:

  




.Op Fl a Ar b




.Op Ar a | b


See also Oo.





  

  
Operating system version for display in the page footer. This is the
      mandatory third macro of any mdoc file.
    
The optional system parameter specifies the relevant
        operating system or environment. It is suggested to leave it
        unspecified, in which case mandoc(1) uses its -Ios argument or,
        if that isn't specified either, sysname and release as
        returned by uname(3).

    
Examples:

  




.Os




.Os KTH/CSC/TCS


.Os BSD 4.3


See also Dd and Dt.





  

  
This macro is obsolete. Use Ft instead; with mandoc(1), both have
      the same effect.
    
Historical mdoc packages described it as “old
        function type (FORTRAN)”.

  

  

  
Format the OpenBSD version provided as an argument, or a default value if
      no argument is provided.
    
Examples:

  




.Ox 4.5




.Ox


See also At, Bsx, Bx, Dx, Fx,
    and Nx.





  

  
An absolute or relative file system path, or a file or directory name. If
      an argument is not provided, the character ‘~’ is used as a
      default.
    
Examples:

  




.Pa /usr/bin/mandoc




.Pa /usr/share/man/man7/mdoc.7


See also Lk.





  

  

    

    Close parenthesised context opened by Po.

  

  
Removes the space between its argument and the following macro. It is
      equivalent to:
    

  




No \&prefix Ns macro
  [argument ...]




The prefix argument is not parsed for macro names or
    delimiters, but used verbatim as if it were escaped.


Examples:


.Pf $ Ar variable_name


.Pf . Ar macro_name


.Pf 0x Ar hex_digits


See also Ns and Sm.





  

  
Multi-line version of Pq.

  

  

    

    Break a paragraph. This will assert vertical space between prior and
      subsequent macros and/or text.
    
Paragraph breaks are not needed before or after Sh or
        Ss macros or before displays (Bd line) or lists
        (Bl) unless the -compact flag is given.

  

  

  
Parenthesised enclosure.
    
See also Po.

  

  

  

    

    Close quoted context opened by Qo.

  

  
In-line literal display. This can be used for complete command invocations
      and for multi-word code examples when an indented display is not desired.
    
See also Dl and Bd -literal.

  

  

  
Multi-line version of Qq.

  

  
Encloses its arguments in "typewriter" double-quotes. Consider
      using Dq.
    
See also Dq, Sq, and Qo.

  

  

  

    

    Close an Rs block. Does not have any tail arguments.

  

  

    

    Begin a bibliographic (“reference”) block. Does not have any
      head arguments. The block macro may only contain %A, %B,
      %C, %D, %I, %J, %N, %O,
      %P, %Q, %R, %T, %U, and %V child
      macros (at least one must be specified).
    
Examples:

  






.Rs
.%A J. E. Hopcroft
.%A J. D. Ullman
.%B Introduction to Automata Theory, Languages, and Computation
.%I Addison-Wesley
.%C Reading, Massachusetts
.%D 1979
.Re








If an Rs block is used within a SEE ALSO section, a
    vertical space is asserted before the rendered output, else the block
    continues on the current line.





  

  
Insert a standard sentence regarding a function call's return value of 0
      on success and -1 on error, with the errno libc global variable set
      on error.
    
If function is not specified, the document's name set
        by Nm is used. Multiple function arguments are treated as
        separate functions.

    
See also Ex.

  

  

  

    

    Close single-quoted context opened by So.

  

  
Begin a new section. For a list of conventional manual sections, see
      MANUAL STRUCTURE. These sections should be used unless it's
      absolutely necessary that custom sections be used.
    
Section names should be unique so that they may be keyed by
        Sx. Although this macro is parsed, it should not consist of child
        node or it may not be linked with Sx.

    
See also Pp, Ss, and Sx.

  

  

  
Switches the spacing mode for output generated from macros.
    
By default, spacing is on. When switched off, no
        white space is inserted between macro arguments and between the output
        generated from adjacent macros, but text lines still get normal spacing
        between words and sentences.

    
When called without an argument, the Sm macro toggles
        the spacing mode. Using this is not recommended because it makes the
        code harder to read.

  

  

  
Multi-line version of Sq.

  

  
Encloses its arguments in ‘typewriter’ single-quotes.
    
See also Dq, Qq, and So.

  

  

  
Begin a new subsection. Unlike with Sh, there is no convention for
      the naming of subsections. Except DESCRIPTION, the conventional
      sections described in MANUAL STRUCTURE rarely have subsections.
    
Sub-section names should be unique so that they may be keyed
        by Sx. Although this macro is parsed, it should not consist of
        child node or it may not be linked with Sx.

    
See also Pp, Sh, and Sx.

  

  

  
Replace an abbreviation for a standard with the full form. The following
      standards are recognised. Where multiple lines are given without a blank
      line in between, they all refer to the same standard, and using the first
      form is recommended.









  

  









  

  
ANSI X3.159-1989 (“ANSI C89”)

  

  
ANSI X3.159-1989 (“ANSI C89”)

  

  
ISO/IEC 9899:1990 (“ISO C90”)

  

  
ISO/IEC 9899:1990 (“ISO C90”)
    

    The original C standard.

  

  
ISO/IEC 9899/AMD1:1995 (“ISO C90, Amendment 1”)

  

  
ISO/IEC 9899/TCOR1:1994 (“ISO C90, Technical Corrigendum
      1”)

  

  
ISO/IEC 9899/TCOR2:1995 (“ISO C90, Technical Corrigendum
      2”)

  

  
ISO/IEC 9899:1999 (“ISO C99”)
    

    The second major version of the C language standard.

  

  
ISO/IEC 9899:2011 (“ISO C11”)
    

    The third major version of the C language standard.









  

  









  

  
IEEE Std 1003.1-1988 (“POSIX.1”)

  

  
IEEE Std 1003.1 (“POSIX.1”)
    

    The original POSIX standard, based on ANSI C.

  

  
IEEE Std 1003.1-1990 (“POSIX.1”)

  

  
ISO/IEC 9945-1:1990 (“POSIX.1”)
    

    The first update of POSIX.1.

  

  
IEEE Std 1003.1b-1993 (“POSIX.1b”)

  

  
IEEE Std 1003.1b (“POSIX.1b”)
    

    Real-time extensions.

  

  
IEEE Std 1003.1c-1995 (“POSIX.1c”)
    

    POSIX thread interfaces.

  

  
IEEE Std 1003.1i-1995 (“POSIX.1i”)
    

    Technical Corrigendum.

  

  
ISO/IEC 9945-1:1996 (“POSIX.1”)

  

  
ISO/IEC 9945-1:1996 (“POSIX.1”)
    

    Includes POSIX.1-1990, 1b, 1c, and 1i.









  

  









  

  
X/Open Portability Guide Issue 3 (“XPG3”)
    

    An XPG4 precursor, published in 1989.

  

  
IEEE Std 1003.2 (“POSIX.2”)

  

  
IEEE Std 1003.2-1992 (“POSIX.2”)

  

  
ISO/IEC 9945-2:1993 (“POSIX.2”)
    

    An XCU4 precursor.

  

  
IEEE Std 1003.2a-1992 (“POSIX.2”)
    

    Updates to POSIX.2.

  

  
X/Open Portability Guide Issue 4 (“XPG4”)
    

    Based on POSIX.1 and POSIX.2, published in 1992.









  

  









  

  
Version 1 of the Single UNIX Specification
    (“SUSv1”)

  

  
X/Open Portability Guide Issue 4, Version 2
      (“XPG4.2”)
    

    This standard was published in 1994. It was used as the basis for UNIX 95
      certification. The following three refer to parts of it.

  

  
X/Open System Interfaces and Headers Issue 4, Version 2
      (“XSH4.2”)

  

  
X/Open Curses Issue 4, Version 2
      (“XCURSES4.2”)

  

  

    

    IEEE Std 1003.1g-2000 (“POSIX.1g”)
    

    Networking APIs, including sockets.

  

  
System V Interface Definition, Fourth Edition
      (“SVID4”),
    

    Published in 1995.









  

  









  

  
Version 2 of the Single UNIX Specification (“SUSv2”)
      This Standard was published in 1997 and is also called X/Open Portability
      Guide version 5. It was used as the basis for UNIX 98 certification. The
      following refer to parts of it.

  

  
X/Open Base Definitions Issue 5 (“XBD5”)

  

  
X/Open System Interfaces and Headers Issue 5
    (“XSH5”)

  

  
X/Open Commands and Utilities Issue 5 (“XCU5”)

  

  
X/Open Networking Services Issue 5 (“XNS5”)

  

  
X/Open Networking Services Issue 5.2 (“XNS5.2”)









  

  









  

  

    

    IEEE Std 1003.1-2001 (“POSIX.1”)

  

  
Version 3 of the Single UNIX Specification (“SUSv3”)
    

    This standard is based on C99, SUSv2, POSIX.1-1996, 1d, and 1j. It is also
      called X/Open Portability Guide version 6. It is used as the basis for
      UNIX 03 certification.

  

  

    

    IEEE Std 1003.1-2004 (“POSIX.1”)
    

    The second and last Technical Corrigendum.









  

  









  

  
IEEE Std 1003.1-2008 (“POSIX.1”)

  

  
Version 4 of the Single UNIX Specification (“SUSv4”)
    

    This standard is also called X/Open Portability Guide version 7.









  

  









  

  
IEEE Std 754-1985
    

    Floating-point arithmetic.

  

  
ISO 8601
    

    Representation of dates and times, published in 1988.

  

  
ISO 8802-3: 1989
    

    Ethernet local area networks.

  

  
IEEE Std 1275-1994 (“Open Firmware”)











  

  
Reference a section or subsection in the same manual page. The referenced
      section or subsection name must be identical to the enclosed argument,
      including whitespace.
    
Examples:

  




.Sx MANUAL STRUCTURE




See also Sh and Ss.





  

  
Request a boldface font.
    
This is most often used to indicate importance or seriousness
        (not to be confused with stress emphasis, see Em). When none of
        the semantic macros fit, it is also adequate for syntax elements that
        have to be given or that appear verbatim.

    
Examples:

  






.Sy Warning :
If
.Sy s
appears in the owner permissions, set-user-ID mode is set.
This utility replaces the former
.Sy dumpdir
program.








See also Em, No, and Ql.





  

  

    

    Table cell separator in Bl -column lists; can only be used
      below It.

  

  
Announce that the next input line starts a definition of the term.
      This macro must appear alone on its own input line. The argument defaults
      to the first argument of the first macro on the next line. The argument
      may not contain whitespace characters, not even when it is quoted. This
      macro is a mandoc(1) extension and is typically ignored by other
      formatters.
    
When viewing terminal output with less(1), the interactive
        :t command can be used to go to the definition of the term
        as described for the MANPAGER variable in man(1); when producing HTML
        output, a fragment identifier (id attribute) is generated, to be
        used for deep linking to this place of the document.

    
In most cases, adding a Tg macro would be redundant
        because mandoc(1) is able to automatically tag most definitions. This
        macro is intended for cases where automatic tagging of a term is
        unsatisfactory, for example if a definition is not tagged automatically
        (false negative) or if places are tagged that do not define the
        term (false positives). When there is at least one Tg
        macro for a term, no other places are automatically marked as
        definitions of that term.

  

  

  
Supported only for compatibility, do not use this in new manuals. Even
      though the macro name (“tradename”) suggests a semantic
      function, historic usage is inconsistent, mostly using it as a
      presentation-level macro to request a small caps font.

  

  

    

    Supported only for compatibility, do not use this in new manuals. Prints out
      “currently under development.”

  

  

    

    Supported only for compatibility, do not use this in new manuals. Prints out
      “UNIX”.

  

  
A variable name.
    
Examples:

  




.Va foo




.Va const char *bar

;

For function arguments and parameters, use Fa instead. For
    declarations of global variables in the SYNOPSIS section, use
    Vt.





  

  
A variable type.
    
This is also used for indicating global variables in the
        SYNOPSIS section, in which case a variable name is also
        specified. Note that it accepts Block partial-implicit syntax
        when invoked as the first macro on an input line in the SYNOPSIS
        section, else it accepts ordinary In-line syntax. In the former
        case, this macro starts a new output line, and a blank line is inserted
        in front if there is a preceding function definition or include
        directive.

    
Examples:

  




.Vt unsigned char




.Vt extern const char * const sys_signame[] ;


For parameters in function prototypes, use Fa instead, for
    function return types Ft, and for variable names outside the
    SYNOPSIS section Va, even when including a type with the name.
    See also MANUAL STRUCTURE.





  

  

    

    Close a scope opened by Xo.

  

  
Extend the header of an It macro or the body of a partial-implicit
      block macro beyond the end of the input line. This macro originally
      existed to work around the 9-argument limit of historic roff(7).

  

  
Link to another manual ("cross-reference").
    
Cross reference the name and section number of
        another man page.

    
Examples:

  




.Xr mandoc 1




.Xr mandoc 1 ;


.Xr mandoc 1 Ns s behaviour










The syntax of a macro depends on its classification. In this
    section, ‘-arg’ refers to macro arguments, which may be
    followed by zero or more ‘parm’ parameters; ‘Yo’
    opens the scope of a macro; and if specified, ‘Yc’ closes it
    out.


The Callable column indicates that the macro may also be
    called by passing its name as an argument to another macro. For example,
    ‘.Op Fl O Ar file’ produces ‘[-O
    file]’. To prevent a macro call and render the macro name
    literally, escape it by prepending a zero-width space,
    ‘\&’. For example, ‘Op \&Fl O’ produces
    ‘[Fl O]’. If a macro is not callable but its name appears as
    an argument to another macro, it is interpreted as opaque text. For example,
    ‘.Fl Sh’ produces ‘-Sh’.


The Parsed column indicates whether the macro may call
    other macros by receiving their names as arguments. If a macro is not parsed
    but the name of another macro appears as an argument, it is interpreted as
    opaque text.


The Scope column, if applicable, describes closure
  rules.






Multi-line scope closed by an explicit closing macro. All macros
    contains bodies; only Bf and (optionally) Bl contain a
  head.






.Yo [-arg [parm...]] [head...]
[body...]
.Yc









  

  

  

    Macro
    Callable
    Parsed
    Scope
  

  

  

  

    Bd
    No
    No
    closed by Ed
  

  

  

  

    Bf
    No
    No
    closed by Ef
  

  

  

  

    Bk
    No
    No
    closed by Ek
  

  

  

  

    Bl
    No
    No
    closed by El
  

  

  

  

    Ed
    No
    No
    opened by Bd
  

  

  

  

    Ef
    No
    No
    opened by Bf
  

  

  

  

    Ek
    No
    No
    opened by Bk
  

  

  

  

    El
    No
    No
    opened by Bl
  












Multi-line scope closed by end-of-file or implicitly by another
    macro. All macros have bodies; some (It -bullet,
    -hyphen, -dash, -enum, -item) don't have heads;
    only one (It in Bl -column) has multiple heads.






.Yo [-arg [parm...]] [head... [Ta head...]]
[body...]









  

  

  

    Macro
    Callable
    Parsed
    Scope
  

  

  

  

    It
    No
    Yes
    closed by It, El
  

  

  

  

    Nd
    No
    No
    closed by Sh
  

  

  

  

    Nm
    No
    Yes
    closed by Nm, Sh, Ss
  

  

  

  

    Sh
    No
    Yes
    closed by Sh
  

  

  

  

    Ss
    No
    Yes
    closed by Sh, Ss
  






Note that the Nm macro is a Block full-implicit
    macro only when invoked as the first macro in a SYNOPSIS section
    line, else it is In-line.








Like block full-explicit, but also with single-line scope. Each
    has at least a body and, in limited circumstances, a head (Fo,
    Eo) and/or tail (Ec).






.Yo [-arg [parm...]] [head...]
[body...]
.Yc [tail...]
.Yo [-arg [parm...]] [head...] [body...] Yc [tail...]









  

  

  

    Macro
    Callable
    Parsed
    Scope
  

  

  

  

    Ac
    Yes
    Yes
    opened by Ao
  

  

  

  

    Ao
    Yes
    Yes
    closed by Ac
  

  

  

  

    Bc
    Yes
    Yes
    closed by Bo
  

  

  

  

    Bo
    Yes
    Yes
    opened by Bc
  

  

  

  

    Brc
    Yes
    Yes
    opened by Bro
  

  

  

  

    Bro
    Yes
    Yes
    closed by Brc
  

  

  

  

    Dc
    Yes
    Yes
    opened by Do
  

  

  

  

    Do
    Yes
    Yes
    closed by Dc
  

  

  

  

    Ec
    Yes
    Yes
    opened by Eo
  

  

  

  

    Eo
    Yes
    Yes
    closed by Ec
  

  

  

  

    Fc
    Yes
    Yes
    opened by Fo
  

  

  

  

    Fo
    No
    No
    closed by Fc
  

  

  

  

    Oc
    Yes
    Yes
    closed by Oo
  

  

  

  

    Oo
    Yes
    Yes
    opened by Oc
  

  

  

  

    Pc
    Yes
    Yes
    closed by Po
  

  

  

  

    Po
    Yes
    Yes
    opened by Pc
  

  

  

  

    Qc
    Yes
    Yes
    opened by Oo
  

  

  

  

    Qo
    Yes
    Yes
    closed by Oc
  

  

  

  

    Re
    No
    No
    opened by Rs
  

  

  

  

    Rs
    No
    No
    closed by Re
  

  

  

  

    Sc
    Yes
    Yes
    opened by So
  

  

  

  

    So
    Yes
    Yes
    closed by Sc
  

  

  

  

    Xc
    Yes
    Yes
    opened by Xo
  

  

  

  

    Xo
    Yes
    Yes
    closed by Xc
  












Like block full-implicit, but with single-line scope closed by the
    end of the line.






.Yo [-arg [val...]] [body...] [res...]









  

  

  

    Macro
    Callable
    Parsed
  

  

  

  

    Aq
    Yes
    Yes
  

  

  

  

    Bq
    Yes
    Yes
  

  

  

  

    Brq
    Yes
    Yes
  

  

  

  

    D1
    No
    Yes
  

  

  

  

    Dl
    No
    Yes
  

  

  

  

    Dq
    Yes
    Yes
  

  

  

  

    En
    Yes
    Yes
  

  

  

  

    Op
    Yes
    Yes
  

  

  

  

    Pq
    Yes
    Yes
  

  

  

  

    Ql
    Yes
    Yes
  

  

  

  

    Qq
    Yes
    Yes
  

  

  

  

    Sq
    Yes
    Yes
  

  

  

  

    Vt
    Yes
    Yes
  






Note that the Vt macro is a Block partial-implicit
    only when invoked as the first macro in a SYNOPSIS section line, else
    it is In-line.








The Ta macro can only be used below It in Bl
    -column lists. It delimits blocks representing table cells; these
    blocks have bodies, but no heads.





  

  

  

    Macro
    Callable
    Parsed
    Scope
  

  

  

  

    Ta
    Yes
    Yes
    closed by Ta, It
  












Closed by the end of the line, fixed argument lengths, and/or
    subsequent macros. In-line macros have only text children. If a number (or
    inequality) of arguments is (n), then the macro accepts an arbitrary number
    of arguments.






.Yo [-arg [val...]] [args...] [res...]
.Yo [-arg [val...]] [args...] Yc...
.Yo [-arg [val...]] arg0 arg1 argN









  

  

  

    Macro
    Callable
    Parsed
    Arguments
  

  

  

  

    %A
    No
    No
    >0
  

  

  

  

    %B
    No
    No
    >0
  

  

  

  

    %C
    No
    No
    >0
  

  

  

  

    %D
    No
    No
    >0
  

  

  

  

    %I
    No
    No
    >0
  

  

  

  

    %J
    No
    No
    >0
  

  

  

  

    %N
    No
    No
    >0
  

  

  

  

    %O
    No
    No
    >0
  

  

  

  

    %P
    No
    No
    >0
  

  

  

  

    %Q
    No
    No
    >0
  

  

  

  

    %R
    No
    No
    >0
  

  

  

  

    %T
    No
    No
    >0
  

  

  

  

    %U
    No
    No
    >0
  

  

  

  

    %V
    No
    No
    >0
  

  

  

  

    Ad
    Yes
    Yes
    >0
  

  

  

  

    An
    Yes
    Yes
    >0
  

  

  

  

    Ap
    Yes
    Yes
    0
  

  

  

  

    Ar
    Yes
    Yes
    n
  

  

  

  

    At
    Yes
    Yes
    1
  

  

  

  

    Bsx
    Yes
    Yes
    n
  

  

  

  

    Bt
    No
    No
    0
  

  

  

  

    Bx
    Yes
    Yes
    n
  

  

  

  

    Cd
    Yes
    Yes
    >0
  

  

  

  

    Cm
    Yes
    Yes
    >0
  

  

  

  

    Db
    No
    No
    1
  

  

  

  

    Dd
    No
    No
    n
  

  

  

  

    Dt
    No
    No
    n
  

  

  

  

    Dv
    Yes
    Yes
    >0
  

  

  

  

    Dx
    Yes
    Yes
    n
  

  

  

  

    Em
    Yes
    Yes
    >0
  

  

  

  

    Er
    Yes
    Yes
    >0
  

  

  

  

    Es
    Yes
    Yes
    2
  

  

  

  

    Ev
    Yes
    Yes
    >0
  

  

  

  

    Ex
    No
    No
    n
  

  

  

  

    Fa
    Yes
    Yes
    >0
  

  

  

  

    Fd
    No
    No
    >0
  

  

  

  

    Fl
    Yes
    Yes
    n
  

  

  

  

    Fn
    Yes
    Yes
    >0
  

  

  

  

    Fr
    Yes
    Yes
    >0
  

  

  

  

    Ft
    Yes
    Yes
    >0
  

  

  

  

    Fx
    Yes
    Yes
    n
  

  

  

  

    Hf
    No
    No
    n
  

  

  

  

    Ic
    Yes
    Yes
    >0
  

  

  

  

    In
    No
    No
    1
  

  

  

  

    Lb
    No
    No
    1
  

  

  

  

    Li
    Yes
    Yes
    >0
  

  

  

  

    Lk
    Yes
    Yes
    >0
  

  

  

  

    Lp
    No
    No
    0
  

  

  

  

    Ms
    Yes
    Yes
    >0
  

  

  

  

    Mt
    Yes
    Yes
    >0
  

  

  

  

    Nm
    Yes
    Yes
    n
  

  

  

  

    No
    Yes
    Yes
    >0
  

  

  

  

    Ns
    Yes
    Yes
    0
  

  

  

  

    Nx
    Yes
    Yes
    n
  

  

  

  

    Os
    No
    No
    n
  

  

  

  

    Ot
    Yes
    Yes
    >0
  

  

  

  

    Ox
    Yes
    Yes
    n
  

  

  

  

    Pa
    Yes
    Yes
    n
  

  

  

  

    Pf
    Yes
    Yes
    1
  

  

  

  

    Pp
    No
    No
    0
  

  

  

  

    Rv
    No
    No
    n
  

  

  

  

    Sm
    No
    No
    <2
  

  

  

  

    St
    No
    Yes
    1
  

  

  

  

    Sx
    Yes
    Yes
    >0
  

  

  

  

    Sy
    Yes
    Yes
    >0
  

  

  

  

    Tg
    No
    No
    <2
  

  

  

  

    Tn
    Yes
    Yes
    >0
  

  

  

  

    Ud
    No
    No
    0
  

  

  

  

    Ux
    Yes
    Yes
    n
  

  

  

  

    Va
    Yes
    Yes
    n
  

  

  

  

    Vt
    Yes
    Yes
    >0
  

  

  

  

    Xr
    Yes
    Yes
    2
  












When a macro argument consists of one single input character
    considered as a delimiter, the argument gets special handling. This does not
    apply when delimiters appear in arguments containing more than one
    character. Consequently, to prevent special handling and just handle it like
    any other argument, a delimiter can be escaped by prepending a zero-width
    space (‘\&’). In text lines, delimiters never need
    escaping, but may be used as normal punctuation.


For many macros, when the leading arguments are opening
    delimiters, these delimiters are put before the macro scope, and when the
    trailing arguments are closing delimiters, these delimiters are put after
    the macro scope. Spacing is suppressed after opening delimiters and before
    closing delimiters. For example,






renders as:




([⟨word⟩

]).

Opening delimiters are:







  
(

  
left parenthesis

  
[

  
left bracket






Closing delimiters are:







  
.

  
period

  
,

  
comma

  
:

  
colon

  
;

  
semicolon

  
)

  
right parenthesis

  
]

  
right bracket

  
?

  
question mark

  
!

  
exclamation mark






Note that even a period preceded by a backslash
    (‘\.’) gets this special handling; use ‘\&.’
    to prevent that.


Many in-line macros interrupt their scope when they encounter
    delimiters, and resume their scope when more arguments follow that are not
    delimiters. For example,






renders as:




-a (-b | -c | -d)
  -e


This applies to both opening and closing delimiters, and also to
    the middle delimiter, which does not suppress spacing:







  
|

  
vertical bar






As a special case, the predefined string \*(Ba is handled and
    rendered in the same way as a plain ‘|’ character. Using this
    predefined string is not recommended in new manuals.


Appending a zero-width space (‘\&’) to the end
    of an input line is also useful to prevent the interpretation of a trailing
    period, exclamation or question mark as the end of a sentence, for example
    when an abbreviation happens to occur at the end of a text or macro input
    line.








In mdoc documents, usage of semantic markup is recommended
    in order to have proper fonts automatically selected; only when no fitting
    semantic markup is available, consider falling back to Physical
    markup macros. Whenever any mdoc macro switches the roff(7) font
    mode, it will automatically restore the previous font when exiting its
    scope. Manually switching the font using the roff(7) ‘\f’ font
    escape sequences is never required.










This section provides an incomplete list of compatibility issues
    between mandoc and GNU troff ("groff").


The following problematic behaviour is found in groff:



  
-

  
Pa does not format its arguments when used in the FILES section
      under certain list types.

  
-

  
Ta can only be called by other macros, but not at the beginning of
      a line.

  
-

  
‘\f’ (font face) and ‘\F’ (font family face)
      Text Decoration escapes behave irregularly when specified within
      line-macro scopes.

  
-

  
Negative scaling units return to prior lines. Instead, mandoc truncates
      them to zero.




The following features are unimplemented in mandoc:



  
-

  
Bd -file file is unsupported for security
    reasons.

  
-

  
Bd -filled does not adjust the right margin, but is an alias
      for Bd -ragged.

  
-

  
Bd -literal does not use a literal font, but is an alias for
      Bd -unfilled.

  
-

  
Bd -offset center and -offset right
      don't work. Groff does not implement centered and flush-right rendering
      either, but produces large indentations.










man(1), mandoc(1), eqn(7), man(7), mandoc_char(7), roff(7),
  tbl(7)


The web page extended documentation for the mdoc language:
    https://mandoc.bsd.lv/mdoc/ provides a few tutorial-style pages for
    beginners, an extensive style guide for advanced authors, and an alphabetic
    index helping to choose the best macros for various kinds of content.


The manual page groff_mdoc(7):
    https://man.voidlinux.org/groff_mdoc contained in the
    “groff” package documents exactly the same language in a
    somewhat different style.








The mdoc language first appeared as a troff macro package
    in 4.4BSD. It was later significantly updated by Werner Lemberg and Ruslan
    Ermilov in groff-1.17. The standalone implementation that is part of the
    mandoc(1) utility written by Kristaps Dzonsons appeared in
    OpenBSD 4.6.








The mdoc reference was written by Kristaps Dzonsons
    <kristaps@bsd.lv>.







  

    July 29, 2021
    Debian