+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+This macro is obsolete.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 . 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 Sx \&Ta Ar cell ...
+.D1 Pf \. Sx \&It Ar cell Op <TAB> 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 the special
+.Sx \&Ta
+block macro or by literal tab characters.
+.Pp
+Using literal tabs is strongly discouraged because they are very
+hard to use correctly and
+.Nm
+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.
+.Pp
+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 portability requires that
+.Sx \&Ta
+is called by other macros: some parsers do not recognize it when
+it appears 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 whitespace before both commas,
+but not the whitespace before the semicolon.