MDOC(7) Standards, Environments, and Macros MDOC(7)

NAME


mdoc - semantic markup language for formatting manual pages

DESCRIPTION


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

MANUAL STRUCTURE


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 Jan 1, 1970
.Dt PROGNAME section
.Os
.Sh NAME
.Nm progname
.Nd one line about what it does
.\" .Sh LIBRARY
.\" For sections 2, 3, and 9 only.
.Sh SYNOPSIS
.Nm progname
.Op Fl options
.Ar
.Sh DESCRIPTION
The
.Nm
utility processes files ...
.\" .Sh IMPLEMENTATION NOTES
.\" .Sh RETURN VALUES
.\" For sections 2, 3, 7, and 9 only.
.\" .Sh CONTEXT
.\" For section 9 functions only.
.\" .Sh ENVIRONMENT
.\" For sections 1, 7, and 8.
.\" .Sh FILES
.\" .Sh EXIT STATUS
.\" For sections 1, 7, and 8.
.\" .Sh EXAMPLES
.\" .Sh DIAGNOSTICS
.\" .Sh ERRORS
.\" For sections 2, 3, 4, and 9 only.
.\" .Sh ARCHITECTURE
.\" .Sh CODE SET INDEPENDENCE
.\" For sections 1, 3, and 8 only.
.\" .Sh INTERFACE STABILITY
.\" .Sh MT-LEVEL
.\" For sections 2 and 3 only.
.\" .Sh SECURITY
.\" .Sh SEE ALSO
.\" .Xr foobar 1
.\" .Sh STANDARDS
.\" .Sh HISTORY
.\" .Sh AUTHORS
.\" .Sh CAVEATS
.\" .Sh BUGS

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 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, 4I, 4P, 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 4D):

.Pa /dev/device_node

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.

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.

CONTEXT
This section lists the contexts in which functions can be called in
section 9. The contexts are user, kernel, or interrupt.

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 sections 1 and 8.
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 and diagnostic messages displayed to the user or sent
to logs. Note that exit status and return values should be
documented in the EXIT STATUS and RETURN VALUES sections.

See Bl -diag.

ERRORS
Documents error handling in sections 2, 3, 7, and 9.

See Er.

ARCHITECTURE
This section is usually absent, but will be present when the
interface is specific to one or more architectures.

CODE SET INDEPENDENCE
Indicates whether the interface operates correctly with various
different code sets. True independent code sets will support not
only ASCII and Extended UNIX Codesets (EUC), but also other multi-
byte encodings such as UTF-8 and GB2312.

Generally there will be some limitations that are fairly standard.
See standards(7) for more information about some of these. Most
interfaces should support at least UTF-8 in addition to ASCII.

INTERFACE STABILITY
Indicates the level of commitment to the interface. Interfaces can
be described with in the following ways:

Standard
Indicates that the interface is defined by one or more
standards bodies. Generally, changes to the interface will
be carefully managed to conform to the relevant standards.
These interfaces are generally the most suitable for use in
portable programs.

Committed
Indicates that the interface is intended to be preserved for
the long-haul, and will rarely, if ever change, and never
without notification (barring extraordinary and extenuating
circumstances). These interfaces are preferred over other
interfaces with the exception of Standard interfaces.

Uncommitted
Indicates that the interface may change. Generally, changes
to these interfaces should be infrequent, and some effort
will be made to address compatibility considerations when
changing or removing such interfaces. However, there is no
firm commitment to the preservation of the interface. Most
often this is applied to interfaces where operational
experience with the interface is still limited and some need
to change may be anticipated.

Consumers should expect to revalidate any Uncommitted
interfaces when crossing release boundaries. Products
intended for use on many releases or intended to support
compatibility with future releases should avoid these
interfaces.

Volatile
The interface can change at any time for any reason. Often
this relates to interfaces that are part of external software
components that are still evolving rapidly. Consumers should
not expect that the interface (either binary or source level)
will be unchanged from one release to the next.

Not-an-Interface
Describes something that is specifically not intended for
programmatic consumption. For example, specific human-
readable output, or the layout of graphical items on a user
interface, may be described this way. Generally programmatic
alternatives to these will be available, and should be used
when programmatic consumption is needed.

Private
This is an internal interface. Generally these interfaces
should only be used within the project, and should not be
used by other programs or modules. The interface can and
will change without notice as the project needs, at any time.

Most often, Private interfaces will lack any documentation
whatsoever, and generally any undocumented interface can be
assumed to be Private.

Obsolete
The interface is not intended for use in new projects or
programs, and may be removed at a future date. The Obsolete
word is a modifier that can be applied to other commitment
levels. For example an Obsolete Committed interface is
unlikely to be removed or changed, but nonetheless new use is
discouraged (perhaps a better newer alternative is present).

MT-LEVEL
This section describes considerations for the interface when used
within programs that use multiple threads. More discussion of these
considerations is made in the MT-Level section of attributes(7). The
interface can be described in the following ways.

Safe Indicates the interface is safe for use within multiple
threads. There may be additional caveats that apply, in
which case those will be described. Note that some
interfaces have semantics which may affect other threads, but
these should be an intrinsic part of the interface rather
than an unexpected side effect. For example, closing a file
in one thread will cause that file to be closed in all
threads.

Unsafe Indicates the interface is unsuitable for concurrent use
within multiple threads. A threaded application may still
make use of the interface, but will be required to provide
external synchronization means to ensure that only a single
thread calls the interface at a time.

MT-Safe
Indicates that the interface is not only safe for concurrent
use, but is designed for such use. For example, a Safe
interface may make use of a global lock to provide safety,
but at reduced internal concurrency, whereas an MT-Safe
interface will be designed to be efficient even when used
concurrently.

Async-Signal-Safe
Indicates that the library is safe for use within a signal
handler. An MT-Safe interface can be made Async-Signal-Safe
by ensuring that it blocks signals when acquiring locks.

Safe with Exceptions
As for Safe but with specific exceptions noted.

MT-Safe with Exceptions
As for MT-Safe but with specific exceptions noted.

SECURITY
Documents any security precautions that operators should consider.

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.

MACRO OVERVIEW


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.

Document preamble and NAME section macros


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)

Sections and cross references


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)

Displays and lists


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)

Spacing control


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

Semantic markup for command line utilities


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)

Semantic markup for function libraries


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)

Various semantic markup


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)

Physical markup


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

Physical enclosures


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

Text production


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

MACRO REFERENCE


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.

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

Ad address
Memory address. Do not use this for postal addresses.

Examples:
.Ad [0,$]
.Ad 0x00000000

An -split | -nosplit | first_name ... last_name
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:

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

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

Ap 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

Aq line
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.

Ar [placeholder ...]
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.

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

v[1-7] | 32v A version of AT&T UNIX.
III AT&T System III UNIX.
V | V.[1-4] 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.

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

Bd -type [-offset width] [-compact]
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:

-centered 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.

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

-literal 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.

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

-unfilled 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:

-offset width 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 mandoc_roff(7).

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

When the argument is missing, -offset is ignored.

-compact Do not assert vertical space before the display.

Examples:

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

See also D1 and Dl.

Bf -emphasis | -literal | -symbolic | Em | Li | Sy
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.

Bk -words
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.

Bl -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 mandoc_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:

-bullet 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.

-column 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.

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

-diag 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.

-enum 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.

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

-hyphen Synonym for -dash.

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

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

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

-tag 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.

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

Examples:
.Bo 1 ,
.Dv BUFSIZ Bc

See also Bq.

Bq line
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.

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

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

Examples:
.Bro 1 , ... ,
.Va n Brc

See also Brq.

Brq line
Encloses its arguments in curly braces.

Examples:
.Brq 1, ..., Va n

See also Bro.

Bsx [version]
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.

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

Bx [version [variant]]
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.

Cd line
Kernel configuration declaration. It is found in pages for BSD and
not used here.

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.

Cm keyword ...
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.
Also useful when specifying configuration options or keys.

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

D1 line
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.

Db 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.

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

Dd $Mdocdate$ | month day, year
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.

Dl line
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.5 \(ba less

See also Ql, Bd -literal, and D1.

Do block
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.

Dq line
Encloses its arguments in "typographic" double-quotes.

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

See also Qq, Sq, and Do.

Dt TITLE section [arch]
Document title for display in the page header. This is the mandatory
second macro of any mdoc file.

Its arguments are as follows:

TITLE 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.

SECTION The manual section. It should correspond to the manual's
filename suffix and defaults to the empty string if
unspecified. This field is optional. To achieve a uniform
appearance of page header lines, it should by convention be
all caps.

arch This specifies the machine architecture a manual page
applies to, where relevant.

Dv 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.

Dx [version]
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.

Ec [closing_delimiter]
Close a scope started by Eo.

The closing_delimiter argument is used as the enclosure tail, for
example, specifying \(rq will emulate Dc.

Ed End a display context started by Bd.

Ef End a font mode context started by Bf.

Ek End a keep context started by Bk.

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

Em word ...
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.

En word ...
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.

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

Er identifier ...
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.

Es opening_delimiter closing_delimiter
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.

Ev identifier ...
Environmental variables such as those specified in environ(7).

Examples:
.Ev DISPLAY
.Ev PATH

See also Dv for general constants.

Ex -std [utility ...]
Insert a standard sentence regarding command exit values of 0 on
success and >0 on failure. This is most often used in section 1 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.

Fa argument ...
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.

Fc End a function context started by Fo.

Fd #directive [argument ...]
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.

Fl [word ...]
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.

Fn funcname [argument ...]
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.

Fo funcname
Begin a function block. This is a multi-line version of Fn.

Invocations usually occur in the following context:

.Ft functype
.Fo funcname
.Fa "argtype argname"
...
.Fc

A Fo scope is closed by Fc.

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

Fr number
This macro is obsolete. No replacement markup is needed.

It was used to show numerical function return values in an italic
font.

Ft functype
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.

Fx [version]
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.

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

Ic keyword ...
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.

In filename
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.

It [head]
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:

.It args

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

.It

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:

.It [args]

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:

.It cell [Ta cell ...]
.It cell [<TAB> cell ...]

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.

Lb libname
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

Li word ...
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.

Lk uri [display_name]
Format a hyperlink.

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

See also Mt.

Lp Deprecated synonym for Pp.

Ms name
Display a mathematical symbol.

Examples:
.Ms sigma
.Ms aleph

Mt localpart@domain
Format a "mailto:" hyperlink.

Examples:
.Mt discuss@manpages.bsd.lv
.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv

Nd line
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.

Nm [name]
The name of the manual page, or -- in particular in section 1 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.

No word ...
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.

Ns 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.

Nx [version]
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.

Oc Close multi-line Oo context.

Oo block
Multi-line version of Op.

Examples:
.Oo
.Op Fl flag Ns Ar value
.Oc

Op line
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.

Os [system [version]]
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(2).

Examples:
.Os
.Os KTH/CSC/TCS
.Os BSD 4.3

See also Dd and Dt.

Ot functype
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)".

Ox [version]
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.

Pa name ...
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/man5/mdoc.5

See also Lk.

Pc Close parenthesised context opened by Po.

Pf prefix macro [argument ...]
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.

Po block
Multi-line version of Pq.

Pp 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.

Pq line
Parenthesised enclosure.

See also Po.

Qc Close quoted context opened by Qo.

Ql line
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.

Qo block
Multi-line version of Qq.

Qq line
Encloses its arguments in "typewriter" double-quotes. Consider using
Dq.

See also Dq, Sq, and Qo.

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

Rs 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.

Rv -std [function ...]
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.

Sc Close single-quoted context opened by So.

Sh TITLE LINE
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.

Sm [on | off]
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.

So block
Multi-line version of Sq.

Sq line
Encloses its arguments in `typewriter' single-quotes.

See also Dq, Qq, and So.

Ss Title line
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.

St -abbreviation
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.

C language standards

-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")
The original C standard.

-isoC-amd1 ISO/IEC 9899/AMD1:1995 ("ISO C90, Amendment 1")

-isoC-tcor1 ISO/IEC 9899/TCOR1:1994 ("ISO C90, Technical
Corrigendum 1")

-isoC-tcor2 ISO/IEC 9899/TCOR2:1995 ("ISO C90, Technical
Corrigendum 2")

-isoC-99 ISO/IEC 9899:1999 ("ISO C99")
The second major version of the C language
standard.

-isoC-2011 ISO/IEC 9899:2011 ("ISO C11")
The third major version of the C language standard.

POSIX.1 before the Single UNIX Specification

-p1003.1-88 IEEE Std 1003.1-1988 ("POSIX.1")
-p1003.1 IEEE Std 1003.1 ("POSIX.1")
The original POSIX standard, based on ANSI C.

-p1003.1-90 IEEE Std 1003.1-1990 ("POSIX.1")
-iso9945-1-90 ISO/IEC 9945-1:1990 ("POSIX.1")
The first update of POSIX.1.

-p1003.1b-93 IEEE Std 1003.1b-1993 ("POSIX.1b")
-p1003.1b IEEE Std 1003.1b ("POSIX.1b")
Real-time extensions.

-p1003.1c-95 IEEE Std 1003.1c-1995 ("POSIX.1c")
POSIX thread interfaces.

-p1003.1i-95 IEEE Std 1003.1i-1995 ("POSIX.1i")
Technical Corrigendum.

-p1003.1-96 ISO/IEC 9945-1:1996 ("POSIX.1")
-iso9945-1-96 ISO/IEC 9945-1:1996 ("POSIX.1")
Includes POSIX.1-1990, 1b, 1c, and 1i.

X/Open Portability Guide version 4 and related standards

-xpg3 X/Open Portability Guide Issue 3 ("XPG3")
An XPG4 precursor, published in 1989.

-p1003.2 IEEE Std 1003.2 ("POSIX.2")
-p1003.2-92 IEEE Std 1003.2-1992 ("POSIX.2")
-iso9945-2-93 ISO/IEC 9945-2:1993 ("POSIX.2")
An XCU4 precursor.

-p1003.2a-92 IEEE Std 1003.2a-1992 ("POSIX.2")
Updates to POSIX.2.

-xpg4 X/Open Portability Guide Issue 4 ("XPG4")
Based on POSIX.1 and POSIX.2, published in 1992.

Single UNIX Specification version 1 and related standards

-susv1 Version 1 of the Single UNIX Specification
("SUSv1")
-xpg4.2 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.

-xsh4.2 X/Open System Interfaces and Headers Issue 4,
Version 2 ("XSH4.2")

-xcurses4.2 X/Open Curses Issue 4, Version 2 ("XCURSES4.2")

-p1003.1g-2000 IEEE Std 1003.1g-2000 ("POSIX.1g")
Networking APIs, including sockets.

-svid4 System V Interface Definition, Fourth Edition
("SVID4"),
Published in 1995.

Single UNIX Specification version 2 and related standards

-susv2 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.

-xbd5 X/Open Base Definitions Issue 5 ("XBD5")

-xsh5 X/Open System Interfaces and Headers Issue 5
("XSH5")

-xcu5 X/Open Commands and Utilities Issue 5 ("XCU5")

-xns5 X/Open Networking Services Issue 5 ("XNS5")
-xns5.2 X/Open Networking Services Issue 5.2 ("XNS5.2")

Single UNIX Specification version 3

-p1003.1-2001 IEEE Std 1003.1-2001 ("POSIX.1")
-susv3 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.

-p1003.1-2004 IEEE Std 1003.1-2004 ("POSIX.1")
The second and last Technical Corrigendum.

Single UNIX Specification version 4

-p1003.1-2008 IEEE Std 1003.1-2008 ("POSIX.1")
-susv4 Version 4 of the Single UNIX Specification
("SUSv4")
This standard is also called X/Open Portability
Guide version 7.

Other standards

-ieee754 IEEE Std 754-1985
Floating-point arithmetic.

-iso8601 ISO 8601
Representation of dates and times, published in
1988.

-iso8802-3 ISO 8802-3: 1989
Ethernet local area networks.

-ieee1275-94 IEEE Std 1275-1994 ("Open Firmware")

Sx Title line
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.

Sy word ...
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.

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

Tg [term]
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.

Tn word ...
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.

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

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

Va [type] identifier ...
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.

Vt type [identifier]
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.

Xc Close a scope opened by Xo.

Xo block
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
mandoc_roff(7).

Xr name section
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

MACRO SYNTAX


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.

Block full-explicit
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

Block full-implicit
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.

Block partial-explicit
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

Block partial-implicit
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.

Special block macro


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

In-line
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

Delimiters


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,

.Aq ( [ word ] ) .

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,

.Fl a ( b | c \*(Ba d ) e

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.

Font handling


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 mandoc_roff(7) font mode, it will automatically
restore the previous font when exiting its scope. Manually switching the
font using the mandoc_roff(7) `\f' font escape sequences is never required.

COMPATIBILITY


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.

SEE ALSO


man(1), mandoc(1), eqn(7), man(7), mandoc_char(7), mandoc_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(4): https://man.voidlinux.org/groff_mdoc
contained in the "groff" package documents exactly the same language in a
somewhat different style.

HISTORY


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.

AUTHORS


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

illumos March 30, 2022 illumos