+.Pp
+Examples:
+.Dl \&.Dt FOO 1
+.Dl \&.Dt FOO 9 i386
+.Pp
+See also
+.Sx \&Dd
+and
+.Sx \&Os .
+.Ss \&Dv
+Defined variables such as preprocessor constants, constant symbols,
+enumeration values, and so on.
+.Pp
+Examples:
+.Dl \&.Dv NULL
+.Dl \&.Dv BUFSIZ
+.Dl \&.Dv STDOUT_FILENO
+.Pp
+See also
+.Sx \&Er
+and
+.Sx \&Ev
+for special-purpose constants,
+.Sx \&Va
+for variable symbols, and
+.Sx \&Fd
+for listing preprocessor variable definitions in the
+.Em SYNOPSIS .
+.Ss \&Dx
+Format the
+.Dx
+version provided as an argument, or a default
+value if no argument is provided.
+.Pp
+Examples:
+.Dl \&.Dx 2.4.1
+.Dl \&.Dx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+and
+.Sx \&Ox .
+.Ss \&Ec
+Close a scope started by
+.Sx \&Eo .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ec Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure tail, for example, specifying \e(rq
+will emulate
+.Sx \&Dc .
+.Ss \&Ed
+End a display context started by
+.Sx \&Bd .
+.Ss \&Ef
+End a font mode context started by
+.Sx \&Bf .
+.Ss \&Ek
+End a keep context started by
+.Sx \&Bk .
+.Ss \&El
+End a list context started by
+.Sx \&Bl .
+.Pp
+See also
+.Sx \&Bl
+and
+.Sx \&It .
+.Ss \&Em
+Request an italic font.
+If the output device does not provide that, underline.
+.Pp
+This is most often used for stress emphasis (not to be confused with
+importance, see
+.Sx \&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,
+.Sx \&Sy
+and
+.Sx \&Ar
+are preferred, respectively.
+.Pp
+Examples:
+.Bd -literal -compact -offset indent
+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.
+.Ed
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Li ,
+.Sx \&No ,
+and
+.Sx \&Sy .
+.Ss \&En
+This macro is obsolete.
+Use
+.Sx \&Eo
+or any of the other enclosure macros.
+.Pp
+It encloses its argument in the delimiters specified by the last
+.Sx \&Es
+macro.
+.Ss \&Eo
+An arbitrary enclosure.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Eo Op Ar TERM
+.Pp
+The
+.Ar TERM
+argument is used as the enclosure head, for example, specifying \e(lq
+will emulate
+.Sx \&Do .
+.Ss \&Er
+Error constants for definitions of the
+.Va errno
+libc global variable.
+This is most often used in section 2 and 3 manual pages.
+.Pp
+Examples:
+.Dl \&.Er EPERM
+.Dl \&.Er ENOENT
+.Pp
+See also
+.Sx \&Dv
+for general constants.
+.Ss \&Es
+This macro is obsolete.
+Use
+.Sx \&Eo
+or any of the other enclosure macros.
+.Pp
+It takes two arguments, defining the delimiters to be used by subsequent
+.Sx \&En
+macros.
+.Ss \&Ev
+Environmental variables such as those specified in
+.Xr environ 7 .
+.Pp
+Examples:
+.Dl \&.Ev DISPLAY
+.Dl \&.Ev PATH
+.Pp
+See also
+.Sx \&Dv
+for general constants.
+.Ss \&Ex
+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.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ex Fl std Op Ar utility ...
+.Pp
+If
+.Ar utility
+is not specified, the document's name set by
+.Sx \&Nm
+is used.
+Multiple
+.Ar utility
+arguments are treated as separate utilities.
+.Pp
+See also
+.Sx \&Rv .
+.Ss \&Fa
+Function argument or parameter.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Fa
+.Qo
+.Op Ar argtype
+.Op Ar argname
+.Qc Ar \&...
+.Ed
+.Pp
+Each argument may be a name and a type (recommended for the
+.Em 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
+.Sx \&Fa
+macro.
+.Pp
+This macro is also used to specify the field name of a structure.
+.Pp
+Most often, the
+.Sx \&Fa
+macro is used in the
+.Em SYNOPSIS
+within
+.Sx \&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
+.Sx \&Fa ,
+the last argument will also have a trailing comma.
+.Pp
+Examples:
+.Dl \&.Fa \(dqconst char *p\(dq
+.Dl \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
+.Dl \&.Fa \(dqchar *\(dq size_t
+.Pp
+See also
+.Sx \&Fo .
+.Ss \&Fc
+End a function context started by
+.Sx \&Fo .
+.Ss \&Fd
+Preprocessor directive, in particular for listing it in the
+.Em SYNOPSIS .
+Historically, it was also used to document include files.
+The latter usage has been deprecated in favour of
+.Sx \&In .
+.Pp
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Fd
+.Li # Ns Ar directive
+.Op Ar argument ...
+.Ed
+.Pp
+Examples:
+.Dl \&.Fd #define sa_handler __sigaction_u.__sa_handler
+.Dl \&.Fd #define SIO_MAXNFDS
+.Dl \&.Fd #ifdef FS_DEBUG
+.Dl \&.Ft void
+.Dl \&.Fn dbg_open \(dqconst char *\(dq
+.Dl \&.Fd #endif
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&In ,
+and
+.Sx \&Dv .
+.Ss \&Fl
+Command-line flag or option.
+Used when listing arguments to command-line utilities.
+Prints a fixed-width hyphen
+.Sq \-
+directly followed by each argument.
+If no arguments are provided, a hyphen is printed followed by a space.
+If the argument is a macro, a hyphen is prefixed to the subsequent macro
+output.
+.Pp
+Examples:
+.Dl ".Fl R Op Fl H | L | P"
+.Dl ".Op Fl 1AaCcdFfgHhikLlmnopqRrSsTtux"
+.Dl ".Fl type Cm d Fl name Pa CVS"
+.Dl ".Fl Ar signal_number"
+.Dl ".Fl o Fl"
+.Pp
+See also
+.Sx \&Cm .
+.Ss \&Fn
+A function name.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Ns Sx \&Fn
+.Op Ar functype
+.Ar funcname
+.Op Oo Ar argtype Oc Ar argname
+.Ed
+.Pp
+Function arguments are surrounded in parenthesis and
+are delimited by commas.
+If no arguments are specified, blank parenthesis are output.
+In the
+.Em SYNOPSIS
+section, this macro starts a new output line,
+and a blank line is automatically inserted between function definitions.
+.Pp
+Examples:
+.Dl \&.Fn \(dqint funcname\(dq \(dqint arg0\(dq \(dqint arg1\(dq
+.Dl \&.Fn funcname \(dqint arg0\(dq
+.Dl \&.Fn funcname arg0
+.Pp
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+When referring to a function documented in another manual page, use
+.Sx \&Xr
+instead.
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fo ,
+and
+.Sx \&Ft .
+.Ss \&Fo
+Begin a function block.
+This is a multi-line version of
+.Sx \&Fn .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Fo Ar funcname
+.Pp
+Invocations usually occur in the following context:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Ft Ar functype
+.br
+.Pf \. Sx \&Fo Ar funcname
+.br
+.Pf \. Sx \&Fa Qq Ar argtype Ar argname
+.br
+\&.\.\.
+.br
+.Pf \. Sx \&Fc
+.Ed
+.Pp
+A
+.Sx \&Fo
+scope is closed by
+.Sx \&Fc .
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fa ,
+.Sx \&Fc ,
+and
+.Sx \&Ft .
+.Ss \&Fr
+This macro is obsolete.
+No replacement markup is needed.
+.Pp
+It was used to show numerical function return values in an italic font.
+.Ss \&Ft
+A function type.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ft Ar functype
+.Pp
+In the
+.Em SYNOPSIS
+section, a new output line is started after this macro.
+.Pp
+Examples:
+.Dl \&.Ft int
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fn ,
+and
+.Sx \&Fo .
+.Ss \&Fx
+Format the
+.Fx
+version provided as an argument, or a default value
+if no argument is provided.
+.Pp
+Examples:
+.Dl \&.Fx 7.1
+.Dl \&.Fx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Nx ,
+and
+.Sx \&Ox .
+.Ss \&Hf
+This macro is not implemented in
+.Xr mandoc 1 .
+.Pp
+It was used to include the contents of a (header) file literally.
+The syntax was:
+.Pp
+.Dl Pf . Sx \&Hf Ar filename
+.Ss \&Ic
+Designate an internal or interactive command.
+This is similar to
+.Sx \&Cm
+but used for instructions rather than values.
+.Pp
+Examples:
+.Dl \&.Ic :wq
+.Dl \&.Ic hash
+.Dl \&.Ic alias
+.Pp
+Note that using
+.Sx \&Bd Fl literal
+or
+.Sx \&D1
+is preferred for displaying code; the
+.Sx \&Ic
+macro is used when referring to specific instructions.
+.Ss \&In
+The name of an include file.
+This macro is most often used in section 2, 3, and 9 manual pages.
+.Pp
+When invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section, the argument is displayed in angle brackets
+and preceded by
+.Qq #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.
+.Pp
+Examples:
+.Dl \&.In sys/types.h
+.Pp
+See also
+.Sx MANUAL STRUCTURE .
+.Ss \&It
+A list item.
+The syntax of this macro depends on the list type.
+.Pp
+Lists
+of type
+.Fl hang ,
+.Fl ohang ,
+.Fl inset ,
+and
+.Fl diag
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Ar args
+.Pp
+Lists of type
+.Fl bullet ,
+.Fl dash ,
+.Fl enum ,
+.Fl hyphen
+and
+.Fl item
+have the following syntax:
+.Pp
+.D1 Pf \. Sx \&It
+.Pp
+with subsequent lines interpreted within the scope of the
+.Sx \&It
+until either a closing
+.Sx \&El
+or another
+.Sx \&It .
+.Pp
+The
+.Fl tag
+list has the following syntax:
+.Pp
+.D1 Pf \. Sx \&It Op Cm args
+.Pp
+Subsequent lines are interpreted as with
+.Fl bullet
+and family.
+The line arguments correspond to the list's left-hand side; body
+arguments correspond to the list's contents.
+.Pp
+The
+.Fl column
+list is the most complicated.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&It Ar cell Op <TAB> Ar cell ...
+.D1 Pf \. Sx \&It Ar cell Op Sx \&Ta Ar cell ...
+.Pp
+The arguments consist of one or more lines of text and macros
+representing a complete table line.
+Cells within the line are delimited by tabs or by the special
+.Sx \&Ta
+block macro.
+The tab cell delimiter may only be used within the
+.Sx \&It
+line itself; on following lines, only the
+.Sx \&Ta
+macro can be used to delimit cells, and
+.Sx \&Ta
+is only recognised as a macro when called by other macros,
+not as the first macro on a line.
+.Pp
+Note that quoted strings may span tab-delimited cells on an
+.Sx \&It
+line.
+For example,
+.Pp
+.Dl .It \(dqcol1 ; <TAB> col2 ;\(dq \&;
+.Pp
+will preserve the semicolon whitespace except for the last.
+.Pp
+See also
+.Sx \&Bl .
+.Ss \&Lb
+Specify a library.
+The syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Lb Ar library
+.Pp
+The
+.Ar library
+parameter may be a system library, such as
+.Cm libz
+or
+.Cm libpam ,
+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
+.Em SYNOPSIS
+section as described in
+.Sx MANUAL STRUCTURE .
+.Pp
+Examples:
+.Dl \&.Lb libz
+.Dl \&.Lb libmandoc
+.Ss \&Li
+Denotes text that should be in a
+.Li literal
+font mode.
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+On terminal output devices, this is often indistinguishable from
+normal text.
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Em ,
+.Sx \&No ,
+and
+.Sx \&Sy .
+.Ss \&Lk
+Format a hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Lk Ar uri Op Ar name
+.Pp
+Examples:
+.Dl \&.Lk http://bsd.lv \(dqThe BSD.lv Project\(dq
+.Dl \&.Lk http://bsd.lv
+.Pp
+See also
+.Sx \&Mt .
+.Ss \&Lp
+Synonym for
+.Sx \&Pp .
+.Ss \&Ms
+Display a mathematical symbol.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ms Ar symbol
+.Pp
+Examples:
+.Dl \&.Ms sigma
+.Dl \&.Ms aleph
+.Ss \&Mt
+Format a
+.Dq mailto:
+hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Mt Ar address
+.Pp
+Examples:
+.Dl \&.Mt discuss@manpages.bsd.lv
+.Dl \&.An Kristaps Dzonsons \&Aq \&Mt kristaps@bsd.lv
+.Ss \&Nd
+A one line description of the manual's content.
+This may only be invoked in the
+.Em SYNOPSIS
+section subsequent the
+.Sx \&Nm
+macro.
+.Pp
+Examples:
+.Dl Pf . Sx \&Nd mdoc language reference
+.Dl Pf . Sx \&Nd format and display UNIX manuals
+.Pp
+The
+.Sx \&Nd
+macro technically accepts child macros and terminates with a subsequent
+.Sx \&Sh
+invocation.
+Do not assume this behaviour: some
+.Xr whatis 1
+database generators are not smart enough to parse more than the line
+arguments and will display macros verbatim.
+.Pp
+See also
+.Sx \&Nm .
+.Ss \&Nm
+The name of the manual page, or \(em in particular in section 1, 6,
+and 8 pages \(em of an additional command or feature documented in
+the manual page.
+When first invoked, the
+.Sx \&Nm
+macro expects a single argument, the name of the manual page.
+Usually, the first invocation happens in the
+.Em 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
+.Sx \&Nm
+macro uses
+.Sx Block full-implicit
+semantics when invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section; otherwise, it uses ordinary
+.Sx In-line
+semantics.
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Sh SYNOPSIS
+\&.Nm cat
+\&.Op Fl benstuv
+\&.Op Ar
+.Ed
+.Pp
+In the
+.Em SYNOPSIS
+of section 2, 3 and 9 manual pages, use the
+.Sx \&Fn
+macro rather than
+.Sx \&Nm
+to mark up the name of the manual page.
+.Ss \&No
+Normal text.
+Closes the scope of any preceding in-line macro.
+When used after physical formatting macros like
+.Sx \&Em
+or
+.Sx \&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.
+.Pp
+Examples:
+.Dl ".Em italic , Sy bold , No and roman"
+.Pp
+.Bd -literal -offset indent -compact
+\&.Sm off
+\&.Cm :C No / Ar pattern No / Ar replacement No /
+\&.Sm on
+.Ed
+.Pp
+See also
+.Sx \&Em ,
+.Sx \&Li ,
+and
+.Sx \&Sy .
+.Ss \&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
+.Sx \&No
+macro.
+.Pp
+This has no effect when invoked at the start of a macro line.
+.Pp
+Examples:
+.Dl ".Ar name Ns = Ns Ar value"
+.Dl ".Cm :M Ns Ar pattern"
+.Dl ".Fl o Ns Ar output"
+.Pp
+See also
+.Sx \&No
+and
+.Sx \&Sm .
+.Ss \&Nx
+Format the
+.Nx
+version provided as an argument, or a default value if
+no argument is provided.
+.Pp
+Examples:
+.Dl \&.Nx 5.01
+.Dl \&.Nx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+and
+.Sx \&Ox .
+.Ss \&Oc
+Close multi-line
+.Sx \&Oo
+context.
+.Ss \&Oo
+Multi-line version of
+.Sx \&Op .
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.Oo
+\&.Op Fl flag Ns Ar value
+\&.Oc
+.Ed
+.Ss \&Op
+Optional part of a command line.
+Prints the argument(s) in brackets.
+This is most often used in the
+.Em SYNOPSIS
+section of section 1 and 8 manual pages.
+.Pp
+Examples:
+.Dl \&.Op \&Fl a \&Ar b
+.Dl \&.Op \&Ar a | b
+.Pp
+See also
+.Sx \&Oo .
+.Ss \&Os
+Operating system version for display in the page footer.
+This is the mandatory third macro of
+any
+.Nm
+file.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Os Op Ar system Op Ar version
+.Pp
+The optional
+.Ar system
+parameter specifies the relevant operating system or environment.
+It is suggested to leave it unspecified, in which case
+.Xr mandoc 1
+uses its
+.Fl Ios
+argument, or, if that isn't specified either,
+.Fa sysname
+and
+.Fa release
+as returned by
+.Xr uname 3 .
+.Pp
+Examples:
+.Dl \&.Os
+.Dl \&.Os KTH/CSC/TCS
+.Dl \&.Os BSD 4.3
+.Pp
+See also
+.Sx \&Dd
+and
+.Sx \&Dt .
+.Ss \&Ot
+This macro is obsolete.
+Use
+.Sx \&Ft
+instead; with
+.Xr mandoc 1 ,
+both have the same effect.
+.Pp
+Historical
+.Nm
+packages described it as
+.Dq "old function type (FORTRAN)" .
+.Ss \&Ox
+Format the
+.Ox
+version provided as an argument, or a default value
+if no argument is provided.
+.Pp
+Examples:
+.Dl \&.Ox 4.5
+.Dl \&.Ox
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+and
+.Sx \&Nx .
+.Ss \&Pa
+An absolute or relative file system path, or a file or directory name.
+If an argument is not provided, the character
+.Sq \(ti
+is used as a default.
+.Pp
+Examples:
+.Dl \&.Pa /usr/bin/mandoc
+.Dl \&.Pa /usr/share/man/man7/mdoc.7
+.Pp
+See also
+.Sx \&Lk .
+.Ss \&Pc
+Close parenthesised context opened by
+.Sx \&Po .
+.Ss \&Pf
+Removes the space between its argument
+.Pq Dq prefix
+and the following macro.
+Its syntax is as follows:
+.Pp
+.D1 .Pf Ar prefix macro arguments ...
+.Pp
+This is equivalent to:
+.Pp
+.D1 .No Ar prefix No \&Ns Ar macro arguments ...
+.Pp
+Examples:
+.Dl ".Pf $ Ar variable_name"
+.Dl ".Pf 0x Ar hex_digits"
+.Pp
+See also
+.Sx \&Ns
+and
+.Sx \&Sm .
+.Ss \&Po
+Multi-line version of
+.Sx \&Pq .
+.Ss \&Pp
+Break a paragraph.
+This will assert vertical space between prior and subsequent macros
+and/or text.
+.Pp
+Paragraph breaks are not needed before or after
+.Sx \&Sh
+or
+.Sx \&Ss
+macros or before displays
+.Pq Sx \&Bd
+or lists
+.Pq Sx \&Bl
+unless the
+.Fl compact
+flag is given.
+.Ss \&Pq
+Parenthesised enclosure.
+.Pp
+See also
+.Sx \&Po .
+.Ss \&Qc
+Close quoted context opened by
+.Sx \&Qo .
+.Ss \&Ql
+In-line literal display.
+This can for example be used for complete command invocations and
+for multi-word code fragments when more specific markup is not
+appropriate and an indented display is not desired.
+While
+.Xr mandoc 1
+always encloses the arguments in single quotes, other formatters
+usually omit the quotes on non-terminal output devices when the
+arguments have three or more characters.
+.Pp
+See also
+.Sx \&Dl
+and
+.Sx \&Bd
+.Fl literal .
+.Ss \&Qo
+Multi-line version of
+.Sx \&Qq .
+.Ss \&Qq
+Encloses its arguments in
+.Qq typewriter
+double-quotes.
+Consider using
+.Sx \&Dq .
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Sq ,
+and
+.Sx \&Qo .
+.Ss \&Re
+Close an
+.Sx \&Rs
+block.
+Does not have any tail arguments.
+.Ss \&Rs
+Begin a bibliographic
+.Pq Dq reference
+block.
+Does not have any head arguments.
+The block macro may only contain
+.Sx \&%A ,
+.Sx \&%B ,
+.Sx \&%C ,
+.Sx \&%D ,
+.Sx \&%I ,
+.Sx \&%J ,
+.Sx \&%N ,
+.Sx \&%O ,
+.Sx \&%P ,
+.Sx \&%Q ,
+.Sx \&%R ,
+.Sx \&%T ,
+.Sx \&%U ,
+and
+.Sx \&%V
+child macros (at least one must be specified).
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.Rs
+\&.%A J. E. Hopcroft
+\&.%A J. D. Ullman
+\&.%B Introduction to Automata Theory, Languages, and Computation
+\&.%I Addison-Wesley
+\&.%C Reading, Massachusettes
+\&.%D 1979
+\&.Re
+.Ed
+.Pp
+If an
+.Sx \&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.
+.Ss \&Rv
+Insert a standard sentence regarding a function call's return value of 0
+on success and \-1 on error, with the
+.Va errno
+libc global variable set on error.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Rv Fl std Op Ar function ...
+.Pp
+If
+.Ar function
+is not specified, the document's name set by
+.Sx \&Nm
+is used.
+Multiple
+.Ar function
+arguments are treated as separate functions.
+.Pp
+See also
+.Sx \&Ex .
+.Ss \&Sc
+Close single-quoted context opened by
+.Sx \&So .
+.Ss \&Sh
+Begin a new section.
+For a list of conventional manual sections, see
+.Sx MANUAL STRUCTURE .
+These sections should be used unless it's absolutely necessary that
+custom sections be used.
+.Pp
+Section names should be unique so that they may be keyed by
+.Sx \&Sx .
+Although this macro is parsed, it should not consist of child node or it
+may not be linked with
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Ss ,
+and
+.Sx \&Sx .
+.Ss \&Sm
+Switches the spacing mode for output generated from macros.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Sm Op Cm on | off
+.Pp
+By default, spacing is
+.Cm on .
+When switched
+.Cm 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.
+.Pp
+When called without an argument, the
+.Sx \&Sm
+macro toggles the spacing mode.
+Using this is not recommended because it makes the code harder to read.
+.Ss \&So
+Multi-line version of
+.Sx \&Sq .
+.Ss \&Sq
+Encloses its arguments in
+.Sq typewriter
+single-quotes.
+.Pp
+See also
+.Sx \&Dq ,
+.Sx \&Qq ,
+and
+.Sx \&So .
+.Ss \&Ss
+Begin a new subsection.
+Unlike with
+.Sx \&Sh ,
+there is no convention for the naming of subsections.
+Except
+.Em DESCRIPTION ,
+the conventional sections described in
+.Sx MANUAL STRUCTURE
+rarely have subsections.
+.Pp
+Sub-section names should be unique so that they may be keyed by
+.Sx \&Sx .
+Although this macro is parsed, it should not consist of child node or it
+may not be linked with
+.Sx \&Sx .
+.Pp
+See also
+.Sx \&Pp ,
+.Sx \&Sh ,
+and
+.Sx \&Sx .
+.Ss \&St
+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.
+.Bl -tag -width 1n
+.It C language standards
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-ansiC
+.St -ansiC
+.It \-ansiC-89
+.St -ansiC-89
+.It \-isoC
+.St -isoC
+.It \-isoC-90
+.St -isoC-90
+.br
+The original C standard.
+.Pp
+.It \-isoC-amd1
+.St -isoC-amd1
+.Pp
+.It \-isoC-tcor1
+.St -isoC-tcor1
+.Pp
+.It \-isoC-tcor2
+.St -isoC-tcor2
+.Pp
+.It \-isoC-99
+.St -isoC-99
+.br
+The second major version of the C language standard.
+.Pp
+.It \-isoC-2011
+.St -isoC-2011
+.br
+The third major version of the C language standard.
+.El
+.It POSIX.1 before the Single UNIX Specification
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-p1003.1-88
+.St -p1003.1-88
+.It \-p1003.1
+.St -p1003.1
+.br
+The original POSIX standard, based on ANSI C.
+.Pp
+.It \-p1003.1-90
+.St -p1003.1-90
+.It \-iso9945-1-90
+.St -iso9945-1-90
+.br
+The first update of POSIX.1.
+.Pp
+.It \-p1003.1b-93
+.St -p1003.1b-93
+.It \-p1003.1b
+.St -p1003.1b
+.br
+Real-time extensions.
+.Pp
+.It \-p1003.1c-95
+.St -p1003.1c-95
+.br
+POSIX thread interfaces.
+.Pp
+.It \-p1003.1i-95
+.St -p1003.1i-95
+.br
+Technical Corrigendum.
+.Pp
+.It \-p1003.1-96
+.St -p1003.1-96
+.It \-iso9945-1-96
+.St -iso9945-1-96
+.br
+Includes POSIX.1-1990, 1b, 1c, and 1i.
+.El
+.It X/Open Portability Guide version 4 and related standards
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-xpg3
+.St -xpg3
+.br
+An XPG4 precursor, published in 1989.
+.Pp
+.It \-p1003.2
+.St -p1003.2
+.It \-p1003.2-92
+.St -p1003.2-92
+.It \-iso9945-2-93
+.St -iso9945-2-93
+.br
+An XCU4 precursor.
+.Pp
+.It \-p1003.2a-92
+.St -p1003.2a-92
+.br
+Updates to POSIX.2.
+.Pp
+.It \-xpg4
+.St -xpg4
+.br
+Based on POSIX.1 and POSIX.2, published in 1992.
+.El
+.It Single UNIX Specification version 1 and related standards
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-susv1
+.St -susv1
+.It \-xpg4.2
+.St -xpg4.2
+.br
+This standard was published in 1994.
+It was used as the basis for UNIX 95 certification.
+The following three refer to parts of it.
+.Pp
+.It \-xsh4.2
+.St -xsh4.2
+.Pp
+.It \-xcurses4.2
+.St -xcurses4.2
+.Pp
+.It \-p1003.1g-2000
+.St -p1003.1g-2000
+.br
+Networking APIs, including sockets.
+.Pp
+.It \-svid4
+.St -svid4 ,
+.br
+Published in 1995.
+.El
+.It Single UNIX Specification version 2 and related standards
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-susv2
+.St -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.
+.Pp
+.It \-xbd5
+.St -xbd5
+.Pp
+.It \-xsh5
+.St -xsh5
+.Pp
+.It \-xcu5
+.St -xcu5
+.Pp
+.It \-xns5
+.St -xns5
+.It \-xns5.2
+.St -xns5.2
+.El
+.It Single UNIX Specification version 3
+.Pp
+.Bl -tag -width "-p1003.1-2001" -compact
+.It \-p1003.1-2001
+.St -p1003.1-2001
+.It \-susv3
+.St -susv3
+.br
+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.
+.Pp
+.It \-p1003.1-2004
+.St -p1003.1-2004
+.br
+The second and last Technical Corrigendum.
+.El
+.It Single UNIX Specification version 4
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-p1003.1-2008
+.St -p1003.1-2008
+.It \-susv4
+.St -susv4
+.br
+This standard is also called
+X/Open Portability Guide version 7.
+.Pp
+.It \-p1003.1-2013
+.St -p1003.1-2013
+.br
+This is the first Technical Corrigendum.
+.El
+.It Other standards
+.Pp
+.Bl -tag -width "-p1003.1g-2000" -compact
+.It \-ieee754
+.St -ieee754
+.br
+Floating-point arithmetic.
+.Pp
+.It \-iso8601
+.St -iso8601
+.br
+Representation of dates and times, published in 1988.
+.Pp
+.It \-iso8802-3
+.St -iso8802-3
+.br
+Ethernet local area networks.
+.Pp
+.It \-ieee1275-94
+.St -ieee1275-94
+.El
+.El
+.Ss \&Sx
+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.
+.Pp
+Examples:
+.Dl \&.Sx MANUAL STRUCTURE
+.Pp
+See also
+.Sx \&Sh
+and
+.Sx \&Ss .
+.Ss \&Sy
+Request a boldface font.
+.Pp
+This is most often used to indicate importance or seriousness (not to be
+confused with stress emphasis, see
+.Sx \&Em ) .
+When none of the semantic macros fit, it is also adequate for syntax
+elements that have to be given or that appear verbatim.
+.Pp
+Examples:
+.Bd -literal -compact -offset indent
+\&.Sy Warning :
+If
+\&.Sy s
+appears in the owner permissions, set-user-ID mode is set.
+This utility replaces the former
+\&.Sy dumpdir
+program.
+.Ed
+.Pp
+See also
+.Sx \&Bf ,
+.Sx \&Em ,
+.Sx \&Li ,
+and
+.Sx \&No .
+.Ss \&Ta
+Table cell separator in
+.Sx \&Bl Fl column
+lists; can only be used below
+.Sx \&It .
+.Ss \&Tn
+Supported only for compatibility, do not use this in new manuals.
+Even though the macro name
+.Pq Dq tradename
+suggests a semantic function, historic usage is inconsistent, mostly
+using it as a presentation-level macro to request a small caps font.
+.Ss \&Ud
+Supported only for compatibility, do not use this in new manuals.
+Prints out
+.Dq currently under development.
+.Ss \&Ux
+Supported only for compatibility, do not use this in new manuals.
+Prints out
+.Dq Ux .
+.Ss \&Va
+A variable name.
+.Pp
+Examples:
+.Dl \&.Va foo
+.Dl \&.Va const char *bar ;
+.Pp
+For function arguments and parameters, use
+.Sx \&Fa
+instead.
+For declarations of global variables in the
+.Em SYNOPSIS
+section, use
+.Sx \&Vt .
+.Ss \&Vt
+A variable type.
+.Pp
+This is also used for indicating global variables in the
+.Em SYNOPSIS
+section, in which case a variable name is also specified.
+Note that it accepts
+.Sx Block partial-implicit
+syntax when invoked as the first macro on an input line in the
+.Em SYNOPSIS
+section, else it accepts ordinary
+.Sx 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.
+.Pp
+Examples:
+.Dl \&.Vt unsigned char
+.Dl \&.Vt extern const char * const sys_signame[] \&;
+.Pp
+For parameters in function prototypes, use
+.Sx \&Fa
+instead, for function return types
+.Sx \&Ft ,
+and for variable names outside the
+.Em SYNOPSIS
+section
+.Sx \&Va ,
+even when including a type with the name.
+See also
+.Sx MANUAL STRUCTURE .
+.Ss \&Xc
+Close a scope opened by
+.Sx \&Xo .
+.Ss \&Xo
+Extend the header of an
+.Sx \&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
+.Xr roff 7 .
+.Ss \&Xr
+Link to another manual
+.Pq Qq cross-reference .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Xr Ar name Op section
+.Pp
+Cross reference the
+.Ar name
+and
+.Ar section
+number of another man page;
+omitting the section number is rarely useful.
+.Pp
+Examples:
+.Dl \&.Xr mandoc 1
+.Dl \&.Xr mandoc 1 \&;
+.Dl \&.Xr mandoc 1 \&Ns s behaviour
+.Ss \&br
+Emits a line-break.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+.Pp
+Consider using
+.Sx \&Pp
+in the event of natural paragraph breaks.
+.Ss \&sp
+Emits vertical space.
+This macro should not be used; it is implemented for compatibility with
+historical manuals.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&sp Op Ar height
+.Pp
+The
+.Ar height
+argument is a scaling width as described in
+.Xr roff 7 .
+If unspecified,
+.Sx \&sp
+asserts a single vertical space.
+.Sh MACRO SYNTAX
+The syntax of a macro depends on its classification.
+In this section,
+.Sq \-arg
+refers to macro arguments, which may be followed by zero or more
+.Sq parm
+parameters;
+.Sq \&Yo
+opens the scope of a macro; and if specified,
+.Sq \&Yc
+closes it out.
+.Pp
+The
+.Em Callable
+column indicates that the macro may also be called by passing its name
+as an argument to another macro.
+For example,
+.Sq \&.Op \&Fl O \&Ar file
+produces
+.Sq Op Fl O Ar file .
+To prevent a macro call and render the macro name literally,
+escape it by prepending a zero-width space,
+.Sq \e& .
+For example,
+.Sq \&Op \e&Fl O
+produces
+.Sq Op \&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,
+.Sq \&.Fl \&Sh
+produces
+.Sq Fl \&Sh .
+.Pp
+The
+.Em 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.
+.Pp
+The
+.Em Scope
+column, if applicable, describes closure rules.
+.Ss Block full-explicit
+Multi-line scope closed by an explicit closing macro.
+All macros contains bodies; only
+.Sx \&Bf
+and
+.Pq optionally
+.Sx \&Bl
+contain a head.
+.Bd -literal -offset indent
+\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
+\(lBbody...\(rB
+\&.Yc
+.Ed
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXX" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&Bd Ta \&No Ta \&No Ta closed by Sx \&Ed
+.It Sx \&Bf Ta \&No Ta \&No Ta closed by Sx \&Ef
+.It Sx \&Bk Ta \&No Ta \&No Ta closed by Sx \&Ek
+.It Sx \&Bl Ta \&No Ta \&No Ta closed by Sx \&El
+.It Sx \&Ed Ta \&No Ta \&No Ta opened by Sx \&Bd
+.It Sx \&Ef Ta \&No Ta \&No Ta opened by Sx \&Bf
+.It Sx \&Ek Ta \&No Ta \&No Ta opened by Sx \&Bk
+.It Sx \&El Ta \&No Ta \&No Ta opened by Sx \&Bl
+.El
+.Ss Block full-implicit
+Multi-line scope closed by end-of-file or implicitly by another macro.
+All macros have bodies; some
+.Po
+.Sx \&It Fl bullet ,
+.Fl hyphen ,
+.Fl dash ,
+.Fl enum ,
+.Fl item
+.Pc
+don't have heads; only one
+.Po
+.Sx \&It
+in
+.Sx \&Bl Fl column
+.Pc
+has multiple heads.
+.Bd -literal -offset indent
+\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead... \(lBTa head...\(rB\(rB
+\(lBbody...\(rB
+.Ed
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXXXXXXXXX" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&It Ta \&No Ta Yes Ta closed by Sx \&It , Sx \&El
+.It Sx \&Nd Ta \&No Ta \&No Ta closed by Sx \&Sh
+.It Sx \&Nm Ta \&No Ta Yes Ta closed by Sx \&Nm , Sx \&Sh , Sx \&Ss
+.It Sx \&Sh Ta \&No Ta Yes Ta closed by Sx \&Sh
+.It Sx \&Ss Ta \&No Ta Yes Ta closed by Sx \&Sh , Sx \&Ss
+.El
+.Pp
+Note that the
+.Sx \&Nm
+macro is a
+.Sx Block full-implicit
+macro only when invoked as the first macro
+in a
+.Em SYNOPSIS
+section line, else it is
+.Sx In-line .
+.Ss 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
+.Po
+.Sx \&Fo ,
+.Sx \&Eo
+.Pc
+and/or tail
+.Pq Sx \&Ec .
+.Bd -literal -offset indent
+\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB
+\(lBbody...\(rB
+\&.Yc \(lBtail...\(rB
+
+\&.Yo \(lB\-arg \(lBparm...\(rB\(rB \(lBhead...\(rB \
+\(lBbody...\(rB \&Yc \(lBtail...\(rB
+.Ed
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&Ac Ta Yes Ta Yes Ta opened by Sx \&Ao
+.It Sx \&Ao Ta Yes Ta Yes Ta closed by Sx \&Ac
+.It Sx \&Bc Ta Yes Ta Yes Ta closed by Sx \&Bo
+.It Sx \&Bo Ta Yes Ta Yes Ta opened by Sx \&Bc
+.It Sx \&Brc Ta Yes Ta Yes Ta opened by Sx \&Bro
+.It Sx \&Bro Ta Yes Ta Yes Ta closed by Sx \&Brc
+.It Sx \&Dc Ta Yes Ta Yes Ta opened by Sx \&Do
+.It Sx \&Do Ta Yes Ta Yes Ta closed by Sx \&Dc
+.It Sx \&Ec Ta Yes Ta Yes Ta opened by Sx \&Eo
+.It Sx \&Eo Ta Yes Ta Yes Ta closed by Sx \&Ec
+.It Sx \&Fc Ta Yes Ta Yes Ta opened by Sx \&Fo
+.It Sx \&Fo Ta \&No Ta \&No Ta closed by Sx \&Fc
+.It Sx \&Oc Ta Yes Ta Yes Ta closed by Sx \&Oo
+.It Sx \&Oo Ta Yes Ta Yes Ta opened by Sx \&Oc
+.It Sx \&Pc Ta Yes Ta Yes Ta closed by Sx \&Po
+.It Sx \&Po Ta Yes Ta Yes Ta opened by Sx \&Pc
+.It Sx \&Qc Ta Yes Ta Yes Ta opened by Sx \&Oo
+.It Sx \&Qo Ta Yes Ta Yes Ta closed by Sx \&Oc
+.It Sx \&Re Ta \&No Ta \&No Ta opened by Sx \&Rs
+.It Sx \&Rs Ta \&No Ta \&No Ta closed by Sx \&Re
+.It Sx \&Sc Ta Yes Ta Yes Ta opened by Sx \&So
+.It Sx \&So Ta Yes Ta Yes Ta closed by Sx \&Sc
+.It Sx \&Xc Ta Yes Ta Yes Ta opened by Sx \&Xo
+.It Sx \&Xo Ta Yes Ta Yes Ta closed by Sx \&Xc
+.El
+.Ss Block partial-implicit
+Like block full-implicit, but with single-line scope closed by the
+end of the line.
+.Bd -literal -offset indent
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBbody...\(rB \(lBres...\(rB
+.Ed
+.Bl -column "MacroX" "CallableX" "ParsedX" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed
+.It Sx \&Aq Ta Yes Ta Yes
+.It Sx \&Bq Ta Yes Ta Yes
+.It Sx \&Brq Ta Yes Ta Yes
+.It Sx \&D1 Ta \&No Ta \&Yes
+.It Sx \&Dl Ta \&No Ta Yes
+.It Sx \&Dq Ta Yes Ta Yes
+.It Sx \&En Ta Yes Ta Yes
+.It Sx \&Op Ta Yes Ta Yes
+.It Sx \&Pq Ta Yes Ta Yes
+.It Sx \&Ql Ta Yes Ta Yes
+.It Sx \&Qq Ta Yes Ta Yes
+.It Sx \&Sq Ta Yes Ta Yes
+.It Sx \&Vt Ta Yes Ta Yes
+.El
+.Pp
+Note that the
+.Sx \&Vt
+macro is a
+.Sx Block partial-implicit
+only when invoked as the first macro
+in a
+.Em SYNOPSIS
+section line, else it is
+.Sx In-line .
+.Ss Special block macro
+The
+.Sx \&Ta
+macro can only be used below
+.Sx \&It
+in
+.Sx \&Bl Fl column
+lists.
+It delimits blocks representing table cells;
+these blocks have bodies, but no heads.
+.Bl -column "MacroX" "CallableX" "ParsedX" "closed by XXXX" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Scope
+.It Sx \&Ta Ta Yes Ta Yes Ta closed by Sx \&Ta , Sx \&It
+.El
+.Ss 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
+.Pq n ,
+then the macro accepts an arbitrary number of arguments.
+.Bd -literal -offset indent
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB \(lBres...\(rB
+
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB \(lBargs...\(rB Yc...
+
+\&.Yo \(lB\-arg \(lBval...\(rB\(rB arg0 arg1 argN
+.Ed
+.Bl -column "MacroX" "CallableX" "ParsedX" "Arguments" -offset indent
+.It Em Macro Ta Em Callable Ta Em Parsed Ta Em Arguments
+.It Sx \&%A Ta \&No Ta \&No Ta >0
+.It Sx \&%B Ta \&No Ta \&No Ta >0
+.It Sx \&%C Ta \&No Ta \&No Ta >0
+.It Sx \&%D Ta \&No Ta \&No Ta >0
+.It Sx \&%I Ta \&No Ta \&No Ta >0
+.It Sx \&%J Ta \&No Ta \&No Ta >0
+.It Sx \&%N Ta \&No Ta \&No Ta >0
+.It Sx \&%O Ta \&No Ta \&No Ta >0
+.It Sx \&%P Ta \&No Ta \&No Ta >0
+.It Sx \&%Q Ta \&No Ta \&No Ta >0
+.It Sx \&%R Ta \&No Ta \&No Ta >0
+.It Sx \&%T Ta \&No Ta \&No Ta >0
+.It Sx \&%U Ta \&No Ta \&No Ta >0
+.It Sx \&%V Ta \&No Ta \&No Ta >0
+.It Sx \&Ad Ta Yes Ta Yes Ta >0
+.It Sx \&An Ta Yes Ta Yes Ta >0
+.It Sx \&Ap Ta Yes Ta Yes Ta 0
+.It Sx \&Ar Ta Yes Ta Yes Ta n
+.It Sx \&At Ta Yes Ta Yes Ta 1
+.It Sx \&Bsx Ta Yes Ta Yes Ta n
+.It Sx \&Bt Ta \&No Ta \&No Ta 0
+.It Sx \&Bx Ta Yes Ta Yes Ta n
+.It Sx \&Cd Ta Yes Ta Yes Ta >0
+.It Sx \&Cm Ta Yes Ta Yes Ta >0
+.It Sx \&Db Ta \&No Ta \&No Ta 1
+.It Sx \&Dd Ta \&No Ta \&No Ta n
+.It Sx \&Dt Ta \&No Ta \&No Ta n
+.It Sx \&Dv Ta Yes Ta Yes Ta >0
+.It Sx \&Dx Ta Yes Ta Yes Ta n
+.It Sx \&Em Ta Yes Ta Yes Ta >0
+.It Sx \&Er Ta Yes Ta Yes Ta >0
+.It Sx \&Es Ta Yes Ta Yes Ta 2
+.It Sx \&Ev Ta Yes Ta Yes Ta >0
+.It Sx \&Ex Ta \&No Ta \&No Ta n
+.It Sx \&Fa Ta Yes Ta Yes Ta >0
+.It Sx \&Fd Ta \&No Ta \&No Ta >0
+.It Sx \&Fl Ta Yes Ta Yes Ta n
+.It Sx \&Fn Ta Yes Ta Yes Ta >0
+.It Sx \&Fr Ta Yes Ta Yes Ta >0
+.It Sx \&Ft Ta Yes Ta Yes Ta >0
+.It Sx \&Fx Ta Yes Ta Yes Ta n
+.It Sx \&Hf Ta \&No Ta \&No Ta n
+.It Sx \&Ic Ta Yes Ta Yes Ta >0
+.It Sx \&In Ta \&No Ta \&No Ta 1
+.It Sx \&Lb Ta \&No Ta \&No Ta 1
+.It Sx \&Li Ta Yes Ta Yes Ta >0
+.It Sx \&Lk Ta Yes Ta Yes Ta >0
+.It Sx \&Lp Ta \&No Ta \&No Ta 0
+.It Sx \&Ms Ta Yes Ta Yes Ta >0
+.It Sx \&Mt Ta Yes Ta Yes Ta >0
+.It Sx \&Nm Ta Yes Ta Yes Ta n
+.It Sx \&No Ta Yes Ta Yes Ta 0
+.It Sx \&Ns Ta Yes Ta Yes Ta 0
+.It Sx \&Nx Ta Yes Ta Yes Ta n
+.It Sx \&Os Ta \&No Ta \&No Ta n
+.It Sx \&Ot Ta Yes Ta Yes Ta >0
+.It Sx \&Ox Ta Yes Ta Yes Ta n
+.It Sx \&Pa Ta Yes Ta Yes Ta n
+.It Sx \&Pf Ta Yes Ta Yes Ta 1
+.It Sx \&Pp Ta \&No Ta \&No Ta 0
+.It Sx \&Rv Ta \&No Ta \&No Ta n
+.It Sx \&Sm Ta \&No Ta \&No Ta <2
+.It Sx \&St Ta \&No Ta Yes Ta 1
+.It Sx \&Sx Ta Yes Ta Yes Ta >0
+.It Sx \&Sy Ta Yes Ta Yes Ta >0
+.It Sx \&Tn Ta Yes Ta Yes Ta >0
+.It Sx \&Ud Ta \&No Ta \&No Ta 0
+.It Sx \&Ux Ta Yes Ta Yes Ta n
+.It Sx \&Va Ta Yes Ta Yes Ta n
+.It Sx \&Vt Ta Yes Ta Yes Ta >0
+.It Sx \&Xr Ta Yes Ta Yes Ta >0
+.It Sx \&br Ta \&No Ta \&No Ta 0
+.It Sx \&sp Ta \&No Ta \&No Ta 1
+.El
+.Ss 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
+.Pq Sq \e& .
+In text lines, delimiters never need escaping, but may be used
+as normal punctuation.
+.Pp
+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.
+For example,
+.Pp
+.D1 Pf \. \&Aq "( [ word ] ) ."
+.Pp
+renders as:
+.Pp
+.D1 Aq ( [ word ] ) .
+.Pp
+Opening delimiters are:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&(
+left parenthesis
+.It \&[
+left bracket
+.El
+.Pp
+Closing delimiters are:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&.
+period
+.It \&,
+comma
+.It \&:
+colon
+.It \&;
+semicolon
+.It \&)
+right parenthesis
+.It \&]
+right bracket
+.It \&?
+question mark
+.It \&!
+exclamation mark
+.El
+.Pp
+Note that even a period preceded by a backslash
+.Pq Sq \e.\&
+gets this special handling; use
+.Sq \e&.
+to prevent that.
+.Pp
+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,
+.Pp
+.D1 Pf \. \&Fl "a ( b | c \e*(Ba d ) e"
+.Pp
+renders as:
+.Pp
+.D1 Fl a ( b | c \*(Ba d ) e
+.Pp
+This applies to both opening and closing delimiters,
+and also to the middle delimiter:
+.Pp
+.Bl -tag -width Ds -offset indent -compact
+.It \&|
+vertical bar
+.El
+.Pp
+As a special case, the predefined string \e*(Ba is handled and rendered
+in the same way as a plain
+.Sq \&|
+character.
+Using this predefined string is not recommended in new manuals.
+.Ss Font handling
+In
+.Nm
+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
+.Sx Physical markup
+macros.
+Whenever any
+.Nm
+macro switches the
+.Xr roff 7
+font mode, it will automatically restore the previous font when exiting
+its scope.
+Manually switching the font using the
+.Xr roff 7
+.Ql \ef
+font escape sequences is never required.
+.Sh COMPATIBILITY
+This section provides an incomplete list of compatibility issues
+between mandoc and GNU troff
+.Pq Qq groff .
+.Pp
+The following problematic behaviour is found in groff:
+.Pp
+.Bl -dash -compact
+.It
+.Sx \&Dd
+with non-standard arguments behaves very strangely.
+When there are three arguments, they are printed verbatim.
+Any other number of arguments is replaced by the current date,
+but without any arguments the string
+.Dq Epoch
+is printed.
+.It
+.Sx \&Lk
+only accepts a single link-name argument; the remainder is misformatted.
+.It
+.Sx \&Pa
+does not format its arguments when used in the FILES section under
+certain list types.
+.It
+.Sx \&Ta
+can only be called by other macros, but not at the beginning of a line.
+.It
+.Sx \&%C
+is not implemented (up to and including groff-1.22.2).
+.It
+.Sq \ef
+.Pq font face
+and
+.Sq \eF
+.Pq font family face
+.Sx Text Decoration
+escapes behave irregularly when specified within line-macro scopes.
+.It
+Negative scaling units return to prior lines.
+Instead, mandoc truncates them to zero.
+.El
+.Pp
+The following features are unimplemented in mandoc:
+.Pp
+.Bl -dash -compact
+.It
+.Sx \&Bd
+.Fl file Ar file
+is unsupported for security reasons.
+.It
+.Sx \&Bd
+.Fl filled
+does not adjust the right margin, but is an alias for
+.Sx \&Bd
+.Fl ragged .
+.It
+.Sx \&Bd
+.Fl literal
+does not use a literal font, but is an alias for
+.Sx \&Bd
+.Fl unfilled .
+.It
+.Sx \&Bd
+.Fl offset Cm center
+and
+.Fl offset Cm right
+don't work.
+Groff does not implement centered and flush-right rendering either,
+but produces large indentations.
+.El
+.Sh SEE ALSO
+.Xr man 1 ,
+.Xr mandoc 1 ,
+.Xr eqn 7 ,
+.Xr man 7 ,
+.Xr mandoc_char 7 ,
+.Xr roff 7 ,
+.Xr tbl 7
+.Sh HISTORY
+The
+.Nm
+language first appeared as a troff macro package in
+.Bx 4.4 .
+It was later significantly updated by Werner Lemberg and Ruslan Ermilov
+in groff-1.17.
+The standalone implementation that is part of the
+.Xr mandoc 1
+utility written by Kristaps Dzonsons appeared in
+.Ox 4.6 .
+.Sh AUTHORS
+The
+.Nm
+reference was written by
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .