+The type must be provided first.
+Secondary arguments are as follows:
+.Bl -tag -width 12n -offset indent
+.It Fl offset Ar val
+Offset by the value of
+.Ar val ,
+which is interpreted as one of the following, specified in order:
+.Bl -item
+.It
+As one of the pre-defined strings
+.Ar indent ,
+the width of standard indentation;
+.Ar indent-two ,
+twice
+.Ar indent ;
+.Ar left ,
+which has no effect;
+.Ar right ,
+which justifies to the right margin; and
+.Ar center ,
+which aligns around an imagined centre axis.
+.It
+As a precalculated width for a named macro.
+The most popular is the imaginary macro
+.Ar \&Ds ,
+which resolves to
+.Ar 6n .
+.It
+As a scaling unit following the syntax described in
+.Sx Scaling Widths .
+.It
+As the calculated string length of the opaque string.
+.El
+.Pp
+If not provided an argument, it will be ignored.
+.It Fl compact
+Do not assert a vertical space before the block.
+.El
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Bd \-unfilled \-offset two-indent \-compact
+ Hello world.
+\&.Ed
+.Ed
+.Pp
+See also
+.Sx \&D1
+and
+.Sx \&Dl .
+.Ss \&Bf
+Change the font mode for a scoped block of text.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bf
+.Oo
+.Fl emphasis | literal | symbolic |
+.Cm \&Em | \&Li | \&Sy
+.Oc
+.Ed
+.Pp
+The
+.Fl emphasis
+and
+.Cm \&Em
+argument are equivalent, as are
+.Fl symbolic
+and
+.Cm \&Sy,
+and
+.Fl literal
+and
+.Cm \&Li .
+Without an argument, this macro does nothing.
+The font mode continues until broken by a new font mode in a nested
+scope or
+.Sx \&Ef
+is encountered.
+.Pp
+See also
+.Sx \&Li ,
+.Sx \&Ef ,
+and
+.Sx \&Sy .
+.Ss \&Bk
+Begins a collection of macros or text not breaking the line.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Bk Fl words
+.Pp
+Subsequent arguments are ignored.
+The
+.Fl words
+argument is required.
+.Pp
+Each line within a keep block is kept intact, so the following example
+will not break within each
+.Sx \&Op
+macro line:
+.Bd -literal -offset indent
+\&.Bk \-words
+\&.Op Fl f Ar flags
+\&.Op Fl o Ar output
+\&.Ek
+.Ed
+.Pp
+Be careful in using over-long lines within a keep block!
+Doing so will clobber the right margin.
+.Ss \&Bl
+Begins a list composed of one or more list entries.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Bl
+.Fl type
+.Op Fl width Ar val
+.Op Fl offset Ar val
+.Op Fl compact
+.Op HEAD ...
+.Ed
+.Pp
+A list is associated with a type, which is a required argument.
+Other arguments are
+.Fl width ,
+defined per-type as accepting a literal or
+.Sx Scaling Widths
+value;
+.Fl offset ,
+also accepting a literal or
+.Sx Scaling Widths
+value setting the list's global offset; and
+.Fl compact ,
+suppressing the default vertical space printed before each list entry.
+A list entry is specified by the
+.Sx \&It
+macro, which consists of a head and optional body (depending on the list
+type).
+A list must specify one of the following list types:
+.Bl -tag -width 12n -offset indent
+.It Fl bullet
+A list offset by a bullet.
+The head of list entries must be empty.
+List entry bodies are positioned after the bullet.
+The
+.Fl width
+argument varies the width of list bodies' left-margins.
+.It Fl column
+A columnated list.
+The
+.Fl width
+argument has no effect.
+The number of columns is specified as parameters to the
+.Sx \&Bl
+macro.
+These dictate the width of columns either as
+.Sx Scaling Widths
+or literal text.
+If the initial macro of a
+.Fl column
+list is not an
+.Sx \&It ,
+an
+.Sx \&It
+context spanning each line is implied until an
+.Sx \&It
+line macro is encountered, at which point list bodies are interpreted as
+described in the
+.Sx \&It
+documentation.
+.It Fl dash
+A list offset by a dash (hyphen).
+The head of list entries must be empty.
+List entry bodies are positioned past the dash.
+The
+.Fl width
+argument varies the width of list bodies' left-margins.
+.It Fl diag
+Like
+.Fl inset ,
+but with additional formatting to the head.
+The
+.Fl width
+argument varies the width of list bodies' left-margins.
+.It Fl enum
+An enumerated list offset by the enumeration from 1.
+The head of list entries must be empty.
+List entry bodies are positioned after the enumeration.
+The
+.Fl width
+argument varies the width of list bodies' left-margins.
+.It Fl hang
+Like
+.Fl tag ,
+but instead of list bodies positioned after the head, they trail the
+head text.
+The
+.Fl width
+argument varies the width of list bodies' left-margins.
+.It Fl hyphen
+Synonym for
+.Fl dash .
+.It Fl inset
+List bodies follow the list head.
+The
+.Fl width
+argument is ignored.
+.It Fl item
+This produces blocks of text.
+The head of list entries must be empty.
+The
+.Fl width
+argument is ignored.
+.It Fl ohang
+List bodies are positioned on the line following the head.
+The
+.Fl width
+argument is ignored.
+.It Fl tag
+A list offset by list entry heads. List entry bodies are positioned
+after the head as specified by the
+.Fl width
+argument.
+.El
+.Pp
+See also
+.Sx \&It .
+.Ss \&Bo
+Begins a block enclosed by square brackets.
+Does not have any head arguments.
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Bo 1 ,
+\&.Dv BUFSIZ \&Bc
+.Ed
+.Pp
+See also
+.Sx \&Bq .
+.Ss \&Bq
+Encloses its arguments in square brackets.
+.Pp
+Examples:
+.D1 \&.Bq 1 , \&Dv BUFSIZ
+.Pp
+.Em Remarks :
+this macro is sometimes abused to emulate optional arguments for
+commands; the correct macros to use for this purpose are
+.Sx \&Op ,
+.Sx \&Oo ,
+and
+.Sx \&Oc .
+.Pp
+See also
+.Sx \&Bo .
+.Ss \&Brc
+Closes a
+.Sx \&Bro
+block. Does not have any tail arguments.
+.Ss \&Bro
+Begins a block enclosed by curly braces.
+Does not have any head arguments.
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Bro 1 , ... ,
+\&.Va n \&Brc
+.Ed
+.Pp
+See also
+.Sx \&Brq .
+.Ss \&Brq
+Encloses its arguments in curly braces.
+.Pp
+Examples:
+.D1 \&.Brq 1 , ... , \&Va n
+.Pp
+See also
+.Sx \&Bro .
+.Ss \&Bsx
+Format the BSD/OS version provided as an argument, or a default value if
+no argument is provided.
+.Pp
+Examples:
+.D1 \&.Bsx 1.0
+.D1 \&.Bsx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+.Sx \&Ox ,
+and
+.Sx \&Ux .
+.Ss \&Bt
+Prints
+.Dq is currently in beta test.
+.Ss \&Bx
+Format the BSD version provided as an argument, or a default value if no
+argument is provided.
+.Pp
+Examples:
+.D1 \&.Bx 4.4
+.D1 \&.Bx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+.Sx \&Ox ,
+and
+.Sx \&Ux .
+.Ss \&Cd
+Configuration declaration.
+This denotes strings accepted by
+.Xr config 8 .
+.Pp
+Examples:
+.D1 \&.Cd device le0 at scode?
+.Pp
+.Em Remarks :
+this macro is commonly abused by using quoted literals to retain
+white-space and align consecutive
+.Sx \&Cd
+declarations.
+This practise is discouraged.
+.Ss \&Cm
+Command modifiers.
+Useful when specifying configuration options or keys.
+.Pp
+Examples:
+.D1 \&.Cm ControlPath
+.D1 \&.Cm ControlMaster
+.Pp
+See also
+.Sx \&Fl .
+.Ss \&D1
+One-line indented display.
+This is formatted by the default rules and is useful for simple indented
+statements.
+It is followed by a newline.
+.Pp
+Examples:
+.D1 \&.D1 \&Fl abcdefgh
+.Pp
+See also
+.Sx \&Bd
+and
+.Sx \&Dl .
+.Ss \&Db
+Start a debugging context.
+This macro is parsed, but generally ignored.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Db Cm on | off
+.Ss \&Dc
+Closes a
+.Sx \&Do
+block. Does not have any tail arguments.
+.Ss \&Dd
+Document date.
+This is the mandatory first macro of any
+.Nm
+manual.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Dd Cm date
+.Pp
+The
+.Cm date
+field may be either
+.Ar $\&Mdocdate$ ,
+which signifies the current manual revision date dictated by
+.Xr cvs 1 ,
+or instead a valid canonical date as specified by
+.Sx Dates .
+If a date does not conform, the current date is used instead.
+.Pp
+Examples:
+.D1 \&.Dd $\&Mdocdate$
+.D1 \&.Dd $\&Mdocdate: July 21 2007$
+.D1 \&.Dd July 21, 2007
+.Pp
+See also
+.Sx \&Dt
+and
+.Sx \&Os .
+.Ss \&Dl
+One-line intended display.
+This is formatted as literal text and is useful for commands and
+invocations.
+It is followed by a newline.
+.Pp
+Examples:
+.D1 \&.Dl % mandoc mdoc.7 | less
+.Pp
+See also
+.Sx \&Bd
+and
+.Sx \&D1 .
+.Ss \&Do
+Begins a block enclosed by double quotes. Does not have any head
+arguments.
+.Pp
+Examples:
+.D1 \&.D1 \&Do April is the cruellest month \&Dc \e(em T.S. Eliot
+.Pp
+See also
+.Sx \&Dq .
+.Ss \&Dq
+Encloses its arguments in double quotes.
+.Pp
+Examples:
+.Bd -literal -offset indent -compact
+\&.Dq April is the cruellest month
+\e(em T.S. Eliot
+.Ed
+.Pp
+See also
+.Sx \&Do .
+.Ss \&Dt
+Document title.
+This is the mandatory second macro of any
+.Nm
+file.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Dt
+.Oo
+.Cm title
+.Oo
+.Cm section
+.Op Cm volume | arch
+.Oc
+.Oc
+.Ed
+.Pp
+Its arguments are as follows:
+.Bl -tag -width Ds -offset Ds
+.It Cm title
+The document's title (name), defaulting to
+.Qq UNKNOWN
+if unspecified.
+It should be capitalised.
+.It Cm section
+The manual section.
+This may be one of
+.Ar 1
+.Pq utilities ,
+.Ar 2
+.Pq system calls ,
+.Ar 3
+.Pq libraries ,
+.Ar 3p
+.Pq Perl libraries ,
+.Ar 4
+.Pq devices ,
+.Ar 5
+.Pq file formats ,
+.Ar 6
+.Pq games ,
+.Ar 7
+.Pq miscellaneous ,
+.Ar 8
+.Pq system utilities ,
+.Ar 9
+.Pq kernel functions ,
+.Ar X11
+.Pq X Window System ,
+.Ar X11R6
+.Pq X Window System ,
+.Ar unass
+.Pq unassociated ,
+.Ar local
+.Pq local system ,
+.Ar draft
+.Pq draft manual ,
+or
+.Ar paper
+.Pq paper .
+It should correspond to the manual's filename suffix and defaults to
+.Qq 1
+if unspecified.
+.It Cm volume
+This overrides the volume inferred from
+.Ar section .
+This field is optional, and if specified, must be one of
+.Ar USD
+.Pq users' supplementary documents ,
+.Ar PS1
+.Pq programmers' supplementary documents ,
+.Ar AMD
+.Pq administrators' supplementary documents ,
+.Ar SMM
+.Pq system managers' manuals ,
+.Ar URM
+.Pq users' reference manuals ,
+.Ar PRM
+.Pq programmers' reference manuals ,
+.Ar KM
+.Pq kernel manuals ,
+.Ar IND
+.Pq master index ,
+.Ar MMI
+.Pq master index ,
+.Ar LOCAL
+.Pq local manuals ,
+.Ar LOC
+.Pq local manuals ,
+or
+.Ar CON
+.Pq contributed manuals .
+.It Cm arch
+This specifies a specific relevant architecture.
+If
+.Cm volume
+is not provided, it may be used in its place, else it may be used
+subsequent that.
+It, too, is optional.
+It must be one of
+.Ar alpha ,
+.Ar amd64 ,
+.Ar amiga ,
+.Ar arc ,
+.Ar arm ,
+.Ar armish ,
+.Ar aviion ,
+.Ar hp300 ,
+.Ar hppa ,
+.Ar hppa64 ,
+.Ar i386 ,
+.Ar landisk ,
+.Ar loongson ,
+.Ar luna88k ,
+.Ar mac68k ,
+.Ar macppc ,
+.Ar mvme68k ,
+.Ar mvme88k ,
+.Ar mvmeppc ,
+.Ar pmax ,
+.Ar sgi ,
+.Ar socppc ,
+.Ar sparc ,
+.Ar sparc64 ,
+.Ar sun3 ,
+.Ar vax ,
+or
+.Ar zaurus .
+.El
+.Pp
+Examples:
+.D1 \&.Dt FOO 1
+.D1 \&.Dt FOO 4 KM
+.D1 \&.Dt FOO 9 i386
+.Pp
+See also
+.Sx \&Dd
+and
+.Sx \&Os .
+.Ss \&Dv
+Defined variables such as preprocessor constants.
+.Pp
+Examples:
+.D1 \&.Dv BUFSIZ
+.D1 \&.Dv STDOUT_FILENO
+.Pp
+See also
+.Sx \&Er .
+.Ss \&Dx
+Format the DragonFly BSD version provided as an argument, or a default
+value if no argument is provided.
+.Pp
+Examples:
+.D1 \&.Dx 2.4.1
+.D1 \&.Dx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+.Sx \&Ox ,
+and
+.Sx \&Ux .
+.Ss \&Ec
+Close a scope started by
+.Sx \&Eo .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ec Op Cm TERM
+.Pp
+The
+.Cm 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
+Ends a font mode context started by
+.Sx \&Bf .
+.Ss \&Ek
+Ends a keep context started by
+.Sx \&Bk .
+.Ss \&El
+Ends a list context started by
+.Sx \&Bl .
+.Pp
+See also
+.Sx \&Bl
+and
+.Sx \&It .
+.Ss \&Em
+Denotes text that should be emphasised.
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Pp
+Examples:
+.D1 \&.Em Warnings!
+.D1 \&.Em Remarks :
+.Ss \&En
+This macro is obsolete and not implemented.
+.Ss \&Eo
+An arbitrary enclosure.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Eo Op Cm TERM
+.Pp
+The
+.Cm TERM
+argument is used as the enclosure head, for example, specifying \e(lq
+will emulate
+.Sx \&Do .
+.Ss \&Er
+Display error constants.
+.Pp
+Examples:
+.D1 \&.Er EPERM
+.D1 \&.Er ENOENT
+.Pp
+See also
+.Sx \&Dv .
+.Ss \&Es
+This macro is obsolete and not implemented.
+.Ss \&Ev
+Environmental variables such as those specified in
+.Xr environ 7 .
+.Pp
+Examples:
+.D1 \&.Ev DISPLAY
+.D1 \&.Ev PATH
+.Ss \&Ex
+Inserts text regarding a utility's exit values.
+This macro must have first the
+.Fl std
+argument specified, then an optional
+.Ar utility .
+If
+.Ar utility
+is not provided, the document's name as stipulated in
+.Sx \&Nm
+is provided.
+.Ss \&Fa
+Function argument.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Fa
+.Op Cm argtype
+.Cm argname
+.Ed
+.Pp
+This may be invoked for names with or without the corresponding type.
+It is also used to specify the field name of a structure.
+Most often, the
+.Sx \&Fa
+macro is used in the
+.Em SYNOPSIS
+within
+.Sx \&Fo
+section 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:
+.D1 \&.Fa \(dqconst char *p\(dq
+.D1 \&.Fa \(dqint a\(dq \(dqint b\(dq \(dqint c\(dq
+.D1 \&.Fa foo
+.Pp
+See also
+.Sx \&Fo .
+.Ss \&Fc
+Ends a function context started by
+.Sx \&Fo .
+.Ss \&Fd
+Historically used to document include files.
+This usage has been deprecated in favour of
+.Sx \&In .
+Do not use this macro.
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+and
+.Sx \&In .
+.Ss \&Fl
+Command-line flag.
+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:
+.D1 \&.Fl a b c
+.D1 \&.Fl \&Pf a b
+.D1 \&.Fl
+.D1 \&.Op \&Fl o \&Ns \&Ar file
+.Pp
+See also
+.Sx \&Cm .
+.Ss \&Fn
+A function name.
+Its syntax is as follows:
+.Bd -ragged -offset indent
+.Pf \. Ns Sx \&Fn
+.Op Cm functype
+.Cm funcname
+.Op Oo Cm argtype Oc Cm argname
+.Ed
+.Pp
+Function arguments are surrounded in parenthesis and
+are delimited by commas.
+If no arguments are specified, blank parenthesis are output.
+.Pp
+Examples:
+.D1 \&.Fn "int funcname" "int arg0" "int arg1"
+.D1 \&.Fn funcname "int arg0"
+.D1 \&.Fn funcname arg0
+.Bd -literal -offset indent -compact
+\&.Ft functype
+\&.Fn funcname
+.Ed
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+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 Cm funcname
+.Pp
+Invocations usually occur in the following context:
+.Bd -ragged -offset indent
+.Pf \. Sx \&Ft Cm functype
+.br
+.Pf \. Sx \&Fo Cm funcname
+.br
+.Pf \. Sx \&Fa Oo Cm argtype Oc Cm argname
+.br
+\.\.\.
+.br
+.Pf \. Sx \&Fc
+.Ed
+.Pp
+A
+.Sx \&Fo
+scope is closed by
+.Pp
+See also
+.Sx MANUAL STRUCTURE ,
+.Sx \&Fa ,
+.Sx \&Fc ,
+and
+.Ss \&Ft
+A function type.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Ft Cm functype
+.Pp
+Examples:
+.D1 \&.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 FreeBSD version provided as an argument, or a default value
+if no argument is provided.
+.Pp
+Examples:
+.D1 \&.Fx 7.1
+.D1 \&.Fx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Nx ,
+.Sx \&Ox ,
+and
+.Sx \&Ux .
+.Ss \&Hf
+This macro is obsolete and not implemented.
+.Ss \&Ic
+Designate an internal or interactive command.
+This is similar to
+.Sx \&Cm
+but used for instructions rather than values.
+.Pp
+Examples:
+.D1 \&.Ic hash
+.D1 \&.Ic alias
+.Pp
+Note that using
+.Sx \&Bd No Fl literal
+or
+.Sx \&D1
+is preferred for displaying code; the
+.Sx \&Ic
+macro is used when referring to specific instructions.
+.Ss \&In
+An
+.Qq include
+file.
+In the
+.Em SYNOPSIS
+section (only if invoked as the line macro), the first argument is
+preceded by
+.Qq #include ,
+the arguments is enclosed in angled braces.
+.Pp
+Examples:
+.D1 \&.In sys/types
+.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 Cm 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 Op Cm args
+.Pp
+The
+.Cm args
+are phrases, a mix of macros and text corresponding to a line column,
+delimited by tabs or the special
+.Sq \&Ta
+pseudo-macro.
+Lines subsequent the
+.Sx \&It
+are interpreted within the scope of the last phrase.
+Calling the pseudo-macro
+.Sq \&Ta
+will open a new phrase scope (this must occur on a macro line to be
+interpreted as a macro). Note that the tab phrase delimiter may only be
+used within the
+.Sx \&It
+line itself.
+Subsequent this, only the
+.Sq \&Ta
+pseudo-macro may be used to delimit phrases.
+Furthermore, note that quoted sections propagate over tab-delimited
+phrases on an
+.Sx \&It ,
+for example,
+.Pp
+.D1 .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 Cm library
+.Pp
+The
+.Cm 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:
+.D1 \&.Lb libz
+.D1 \&.Lb mdoc
+.Ss \&Li
+Denotes text that should be in a literal font mode.
+Note that this is a presentation term and should not be used for
+stylistically decorating technical terms.
+.Ss \&Lk
+Format a hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Lk Cm uri Op Cm name
+.Pp
+Examples:
+.D1 \&.Lk http://bsd.lv "The BSD.lv Project"
+.D1 \&.Lk http://bsd.lv
+.Pp
+See also
+.Sx \&Mt .
+.Ss \&Lp
+Synonym for
+.Sx \&Pp .
+.Ss \&Ms
+.Ss \&Mt
+Format a
+.Qq mailto:
+hyperlink.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Mt Cm address
+.Pp
+Examples:
+.D1 \&.Mt discuss@manpages.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:
+.D1 \&.Sx \&Nd mdoc language reference
+.D1 \&.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
+A
+.Qq noop
+macro used to terminate prior macro contexts.
+.Pp
+Examples:
+.D1 \&.Sx \&Fl ab \&No cd \&Fl ef
+.Ss \&Ns
+.Ss \&Nx
+Format the NetBSD version provided as an argument, or a default value if
+no argument is provided.
+.Pp
+Examples:
+.D1 \&.Nx 5.01
+.D1 \&.Nx
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+.Sx \&Ox ,
+and
+.Sx \&Ux .
+.Ss \&Oc
+Closes multi-line
+.Sx \&Oo
+context.
+.Ss \&Oo
+Multi-line version of
+.Sx \&Op .
+.Pp
+Examples:
+.Bd -literal -offset indent
+\&.Oo
+\&.Op Fl flag Ns Ar value
+\&.Oc
+.Ed
+.Ss \&Op
+Command-line option.
+Used when listing options to command-line utilities.
+Prints the argument(s) in brackets.
+.Pp
+Examples:
+.D1 \&.Op \&Fl a \&Ar b
+.D1 \&.Op \&Ar a | b
+.Pp
+See also
+.Sx \&Oo .
+.Ss \&Os
+Document operating system version.
+This is the mandatory third macro of
+any
+.Nm
+file.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Os Op Cm system
+.Pp
+The optional
+.Cm system
+parameter specifies the relevant operating system or environment.
+Left unspecified, it defaults to the local operating system version.
+This is the suggested form.
+.Pp
+Examples:
+.D1 \&.Os
+.D1 \&.Os KTH/CSC/TCS
+.D1 \&.Os BSD 4.3
+.Pp
+See also
+.Sx \&Dd
+and
+.Sx \&Dt .
+.Ss \&Ot
+Unknown usage.
+.Pp
+.Em Remarks :
+this macro has been deprecated.
+.Ss \&Ox
+Format the OpenBSD version provided as an argument, or a default value
+if no argument is provided.
+.Pp
+Examples:
+.D1 \&.Ox 4.5
+.D1 \&.Ox
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+and
+.Sx \&Ux .
+.Ss \&Pa
+A file-system path.
+.Pp
+Examples:
+.D1 \&.Pa /usr/bin/mandoc
+.D1 \&.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
+.Pq Qq prefix
+between its arguments.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. \&Pf Cm prefix suffix
+.Pp
+The
+.Cm suffix
+argument may be a macro.
+.Pp
+Examples:
+.D1 \&.Pf \e. \&Sx \&Pf \&Cm prefix suffix
+.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.
+.Ss \&Pq
+Parenthesised enclosure.
+.Pp
+See also
+.Sx \&Po .
+.Ss \&Qc
+.Ss \&Ql
+.Ss \&Qo
+.Ss \&Qq
+.Ss \&Re
+Closes a
+.Sx \&Rs
+block.
+Does not have any tail arguments.
+.Ss \&Rs
+Begins 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
+.Ss \&Sc
+.Ss \&Sh
+.Ss \&Sm
+Switches the spacing mode for output generated from macros.
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Sm 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 free-form text lines
+still get normal spacing between words and sentences.
+.Ss \&So
+.Ss \&Sq
+.Ss \&Ss
+.Ss \&St
+.Ss \&Sx
+.Ss \&Sy
+.Ss \&Tn
+.Ss \&Ud
+Prints out
+.Dq currently under development.
+.Ss \&Ux
+Format the UNIX name.
+Accepts no argument.
+.Pp
+Examples:
+.D1 \&.Ux
+.Pp
+See also
+.Sx \&At ,
+.Sx \&Bsx ,
+.Sx \&Bx ,
+.Sx \&Dx ,
+.Sx \&Fx ,
+.Sx \&Nx ,
+and
+.Sx \&Ox .
+.Ss \&Va
+A variable name.
+.Pp
+Examples:
+.D1 \&.Va foo
+.D1 \&.Va const char *bar ;
+.Ss \&Vt
+A variable type.
+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 in the
+.Em SYNOPSIS
+section, else it accepts ordinary
+.Sx In-line
+syntax.
+.Pp
+Note that this should not be confused with
+.Sx \&Ft ,
+which is used for function return types.
+.Pp
+Examples:
+.D1 \&.Vt unsigned char
+.D1 \&.Vt extern const char * const sys_signame[] \&;
+.Pp
+See also
+.Sx MANUAL STRUCTURE
+and
+.Sx \&Va .
+.Ss \&Xc
+Close a scope opened by
+.Sx \&Xo .
+.Ss \&Xo
+Open an extension scope.
+This macro originally existed to extend the 9-argument limit of troff;
+since this limit has been lifted, the macro has been deprecated.
+.Ss \&Xr
+Link to another manual
+.Pq Qq cross-reference .
+Its syntax is as follows:
+.Pp
+.D1 Pf \. Sx \&Xr Cm name section
+.Pp
+The
+.Cm name
+and
+.Cm section
+are the name and section of the linked manual.
+If
+.Cm section
+is followed by non-punctuation, an
+.Sx \&Ns
+is inserted into the token stream.
+This behaviour is for compatibility with
+.Xr groff 1 .
+.Pp
+Examples:
+.D1 \&.Xr mandoc 1
+.D1 \&.Xr mandoc 1 \&;
+.D1 \&.Xr mandoc 1 \&Ns s behaviour
+.Ss \&br
+.Ss \&sp
+.Sh COMPATIBILITY
+This section documents compatibility between mandoc and other other
+troff implementations, at this time limited to GNU troff
+.Pq Qq groff .
+The term
+.Qq historic groff
+refers to groff versions before the
+.Pa doc.tmac
+file re-write
+.Pq somewhere between 1.15 and 1.19 .
+.Pp
+Heirloom troff, the other significant troff implementation accepting
+\-mdoc, is similar to historic groff.
+.Pp
+.Bl -dash -compact
+.It
+Old groff fails to assert a newline before
+.Sx \&Bd Fl ragged compact .
+.It
+groff behaves inconsistently when encountering
+.Pf non- Sx \&Fa
+children of
+.Sx \&Fo
+regarding spacing between arguments.
+In mandoc, this is not the case: each argument is consistently followed
+by a single space and the trailing
+.Sq \&)
+suppresses prior spacing.
+.It
+groff behaves inconsistently when encountering
+.Sx \&Ft
+and
+.Sx \&Fn
+in the
+.Em SYNOPSIS :
+at times newline(s) are suppressed depending on whether a prior
+.Sx \&Fn
+has been invoked.
+In mandoc, this is not the case.
+See
+.Sx \&Ft
+and
+.Sx \&Fn
+for the normalised behaviour.
+.It
+Historic groff does not break before an
+.Sx \&Fn
+when not invoked as the line macro in the
+.Em SYNOPSIS
+section.
+.It
+Historic groff formats the
+.Sx \&In
+badly: trailing arguments are trashed and
+.Em SYNOPSIS
+is not specially treated.
+.It
+groff does not accept the
+.Sq \&Ta
+pseudo-macro as a line macro.
+mandoc does.
+.It
+The comment syntax
+.Sq \e."
+is no longer accepted.
+.It
+In groff, the
+.Sx \&Pa
+macro does not format its arguments when used in the FILES section under
+certain list types.
+mandoc does.
+.It
+Historic groff does not print a dash for empty
+.Sx \&Fl
+arguments.
+mandoc and newer groff implementations do.
+.It
+groff behaves irregularly when specifying
+.Sq \ef
+.Sx Text Decoration
+within line-macro scopes.
+mandoc follows a consistent system.
+.It
+In mandoc, negative scaling units are truncated to zero; groff would
+move to prior lines.
+Furthermore, the
+.Sq f
+scaling unit, while accepted, is rendered as the default unit.
+.It
+In quoted literals, groff allowed pair-wise double-quotes to produce a
+standalone double-quote in formatted output.
+This idiosyncratic behaviour is not applicable in mandoc.
+.It
+Display offsets
+.Sx \&Bd
+.Fl offset Ar center
+and
+.Fl offset Ar right
+are disregarded in mandoc.
+Furthermore, troff specifies a
+.Fl file Ar file
+argument that is not supported in mandoc.
+Lastly, since text is not right-justified in mandoc (or even groff),
+.Fl ragged
+and
+.Fl filled
+are aliases, as are
+.Fl literal
+and
+.Fl unfilled .
+.It
+Historic groff has many un-callable macros.
+Most of these (excluding some block-level macros) are now callable.
+.It
+The vertical bar
+.Sq \(ba
+made historic groff
+.Qq go orbital
+but has been a proper delimiter since then.
+.It
+.Sx \&It Fl nested
+is assumed for all lists (it wasn't in historic groff): any list may be
+nested and
+.Fl enum
+lists will restart the sequence only for the sub-list.
+.It
+Some manuals use
+.Sx \&Li
+incorrectly by following it with a reserved character and expecting the
+delimiter to render.
+This is not supported in mandoc.
+.It
+In groff, the
+.Sx \&Cd ,
+.Sx \&Er ,
+.Sx \&Ex ,
+and
+.Sx \&Rv
+macros were stipulated only to occur in certain manual sections.
+mandoc does not have these restrictions.
+.It
+Newer groff and mandoc print
+.Qq AT&T UNIX
+prior to unknown arguments of
+.Sx \&At ;
+older groff did nothing.
git.ckatri.com / mandoc.git / blobdiff