-.\" $Id: mandoc_char.7,v 1.3 2009/04/12 19:29:53 kristaps Exp $
+.\" $Id: mandoc_char.7,v 1.66 2017/06/02 12:43:52 schwarze Exp $
.\"
-.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@openbsd.org>
+.\" Copyright (c) 2003 Jason McIntyre <jmc@openbsd.org>
+.\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+.\" Copyright (c) 2011, 2013, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
-.\" purpose with or without fee is hereby granted, provided that the
-.\" above copyright notice and this permission notice appear in all
-.\" copies.
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
.\"
-.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
-.\" WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
-.\" WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
-.\" AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
-.\" DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
-.\" PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
-.\" TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-.\" PERFORMANCE OF THIS SOFTWARE.
-.\"
-.Dd $Mdocdate: April 12 2009 $
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: June 2 2017 $
.Dt MANDOC_CHAR 7
.Os
-.\" SECTION
.Sh NAME
.Nm mandoc_char
.Nd mandoc special characters
-.\" SECTION
.Sh DESCRIPTION
-This documents the special characters accepted by
+This page documents the
+.Xr roff 7
+escape sequences accepted by
.Xr mandoc 1
-to format
+to represent special characters in
.Xr mdoc 7
and
.Xr man 7
-documents. Specific output devices of
+documents.
+.Pp
+The rendering depends on the
+.Xr mandoc 1
+output mode; in ASCII output, most characters are completely
+unintelligible.
+For that reason, using any of the special characters documented here,
+except those discussed in the
+.Sx DESCRIPTION ,
+is strongly discouraged; they are supported merely for backwards
+compatibility with existing documents.
+.Pp
+In particular, in English manual pages, do not use special-character
+escape sequences to represent national language characters in author
+names; instead, provide ASCII transcriptions of the names.
+.Ss Dashes and Hyphens
+In typography there are different types of dashes of various width:
+the hyphen (-),
+the minus sign (\(mi),
+the en-dash (\(en),
+and the em-dash (\(em).
+.Pp
+Hyphens are used for adjectives;
+to separate the two parts of a compound word;
+or to separate a word across two successive lines of text.
+The hyphen does not need to be escaped:
+.Bd -unfilled -offset indent
+blue-eyed
+lorry-driver
+.Ed
+.Pp
+If a word on a text input line contains a hyphen, a formatter may decide
+to insert an output line break after the hyphen if that helps filling
+the current output line, but the whole word would overflow the line.
+If it is important that the word is not broken across lines in this
+way, a zero-width space
+.Pq Sq \e&
+can be inserted before or after the hyphen.
+While
+.Xr mandoc 1
+never breaks the output line after hyphens adjacent to a zero-width
+space, after any of the other dash- or hyphen-like characters
+represented by escape sequences, or after hyphens inside words in
+macro arguments, other software may not respect these rules and may
+break the line even in such cases.
+.Pp
+Some
+.Xr roff 7
+implementations contains dictionaries allowing to break the line
+at syllable boundaries even inside words that contain no hyphens.
+Such automatic hyphenation is not supported by
.Xr mandoc 1 ,
-dictated by the
-.Fl T Ns Ar output
-argument, will properly render these sequences.
+which only breaks the line at whitespace, and inside words only
+after existing hyphens.
.Pp
-Both
-.Xr mdoc 7
+The mathematical minus sign is used for negative numbers or subtraction.
+It should be written as
+.Sq \e(mi :
+.Bd -unfilled -offset indent
+a = 3 \e(mi 1;
+b = \e(mi2;
+.Ed
+.Pp
+The en-dash is used to separate the two elements of a range,
+or can be used the same way as an em-dash.
+It should be written as
+.Sq \e(en :
+.Bd -unfilled -offset indent
+pp. 95\e(en97.
+Go away \e(en or else!
+.Ed
+.Pp
+The em-dash can be used to show an interruption
+or can be used the same way as colons, semi-colons, or parentheses.
+It should be written as
+.Sq \e(em :
+.Bd -unfilled -offset indent
+Three things \e(em apples, oranges, and bananas.
+This is not that \e(em rather, this is that.
+.Ed
+.Pp
+Note:
+hyphens, minus signs, and en-dashes look identical under normal ASCII output.
+Other formats, such as PostScript, render them correctly,
+with differing widths.
+.Ss Spaces
+To separate words in normal text, for indenting and alignment
+in literal context, and when none of the following special cases apply,
+just use the normal space character
+.Pq Sq \ .
+.Pp
+When filling text, output lines may be broken between words, i.e. at space
+characters.
+To prevent a line break between two particular words,
+use the unpaddable non-breaking space escape sequence
+.Pq Sq \e\ \&
+instead of the normal space character.
+For example, the input string
+.Dq number\e\ 1
+will be kept together as
+.Dq number\ 1
+on the same output line.
+.Pp
+On request and macro lines, the normal space character serves as an
+argument delimiter.
+To include whitespace into arguments, quoting is usually the best choice;
+see the MACRO SYNTAX section in
+.Xr roff 7 .
+In some cases, using the non-breaking space escape sequence
+.Pq Sq \e\ \&
+may be preferable.
+.Pp
+To escape macro names and to protect whitespace at the end
+of input lines, the zero-width space
+.Pq Sq \e&
+is often useful.
+For example, in
+.Xr mdoc 7 ,
+a normal space character can be displayed in single quotes in either
+of the following ways:
+.Pp
+.Dl .Sq \(dq \(dq
+.Dl .Sq \e \e&
+.Ss Quotes
+On request and macro lines, the double-quote character
+.Pq Sq \(dq
+is handled specially to allow quoting.
+One way to prevent this special handling is by using the
+.Sq \e(dq
+escape sequence.
+.Pp
+Note that on text lines, literal double-quote characters can be used
+verbatim.
+All other quote-like characters can be used verbatim as well,
+even on request and macro lines.
+.Ss Accents
+In output modes supporting such special output characters, for example
+.Fl T Cm pdf ,
+and sometimes less consistently in
+.Fl T Cm utf8 ,
+some
+.Xr roff 7
+formatters convert the following ASCII input characters to the
+following Unicode special output characters:
+.Bl -column x(ga U+2018 -offset indent
+.It \(ga Ta U+2018 Ta left single quotation mark
+.It \(aq Ta U+2019 Ta right single quotation mark
+.It \(ti Ta U+02DC Ta small tilde
+.It \(ha Ta U+02C6 Ta modifier letter circumflex
+.El
+.Pp
+In prose, this automatic substitution is often desirable;
+but when these characters have to be displayed as plain ASCII
+characters, for example in source code samples, they require
+escaping to render as follows:
+.Bl -column x(ga U+2018 -offset indent
+.It \e(ga Ta U+0060 Ta grave accent
+.It \e(aq Ta U+0027 Ta apostrophe
+.It \e(ti Ta U+007E Ta tilde
+.It \e(ha Ta U+005E Ta circumflex accent
+.El
+.Ss Periods
+The period
+.Pq Sq \&.
+is handled specially at the beginning of an input line,
+where it introduces a
+.Xr roff 7
+request or a macro, and when appearing alone as a macro argument in
+.Xr mdoc 7 .
+In such situations, prepend a zero-width space
+.Pq Sq \e&.
+to make it behave like normal text.
+.Pp
+Do not use the
+.Sq \e.
+escape sequence.
+It does not prevent special handling of the period.
+.Ss Backslashes
+To include a literal backslash
+.Pq Sq \e
+into the output, use the
+.Pq Sq \ee
+escape sequence.
+.Pp
+Note that doubling it
+.Pq Sq \e\e
+is not the right way to output a backslash.
+Because
+.Xr mandoc 1
+does not implement full
+.Xr roff 7
+functionality, it may work with
+.Xr mandoc 1 ,
+but it may have weird effects on complete
+.Xr roff 7
+implementations.
+.Sh SPECIAL CHARACTERS
+Special characters are encoded as
+.Sq \eX
+.Pq for a one-character escape ,
+.Sq \e(XX
+.Pq two-character ,
and
-.Xr man 7
-encode special characters with slightly different semantics; consult the
-respective manuals for these escapes.
-.Pp
-Grammatic:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(em
-.Pq em-dash
-.It \e(en
-.Pq en-dash
-.It \e-
-.Pq hyphen
-.It \e\e
-.Pq back-slash
-.It \e'
-.Pq apostrophe
-.It \e`
-.Pq back-tick
-.It \e
-.Pq space
-.It \e.
-.Pq period
-.It \e(r!
-.Pq upside-down exclamation
-.It \e(r?
-.Pq upside-down question
+.Sq \e[N]
+.Pq N-character .
+For details, see the
+.Em Special Characters
+subsection of the
+.Xr roff 7
+manual.
+.Pp
+Spacing:
+.Bl -column "Input" "Description" -offset indent -compact
+.It Em Input Ta Em Description
+.It Sq \e\ \& Ta unpaddable non-breaking space
+.It \e\(ti Ta paddable non-breaking space
+.It \e0 Ta unpaddable, breaking digit-width space
+.It \e| Ta one-sixth \e(em narrow space, zero width in nroff mode
+.It \e^ Ta one-twelfth \e(em half-narrow space, zero width in nroff
+.It \e& Ta zero-width space
+.It \e% Ta zero-width space allowing hyphenation
+.El
+.Pp
+Lines:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(ba Ta \(ba Ta bar
+.It \e(br Ta \(br Ta box rule
+.It \e(ul Ta \(ul Ta underscore
+.It \e(rn Ta \(rn Ta overline
+.It \e(bb Ta \(bb Ta broken bar
+.It \e(sl Ta \(sl Ta forward slash
+.It \e(rs Ta \(rs Ta backward slash
+.El
+.Pp
+Text markers:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(ci Ta \(ci Ta circle
+.It \e(bu Ta \(bu Ta bullet
+.It \e(dd Ta \(dd Ta double dagger
+.It \e(dg Ta \(dg Ta dagger
+.It \e(lz Ta \(lz Ta lozenge
+.It \e(sq Ta \(sq Ta white square
+.It \e(ps Ta \(ps Ta paragraph
+.It \e(sc Ta \(sc Ta section
+.It \e(lh Ta \(lh Ta left hand
+.It \e(rh Ta \(rh Ta right hand
+.It \e(at Ta \(at Ta at
+.It \e(sh Ta \(sh Ta hash (pound)
+.It \e(CR Ta \(CR Ta carriage return
+.It \e(OK Ta \(OK Ta check mark
+.It \e(CL Ta \(CL Ta club suit
+.It \e(SP Ta \(SP Ta spade suit
+.It \e(HE Ta \(HE Ta heart suit
+.It \e(DI Ta \(DI Ta diamond suit
+.El
+.Pp
+Legal symbols:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(co Ta \(co Ta copyright
+.It \e(rg Ta \(rg Ta registered
+.It \e(tm Ta \(tm Ta trademarked
.El
-.\" PARAGRAPH
-.Pp
-Enclosures:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(lh
-.Pq left hand
-.It \e(rh
-.Pq right hand
-.It \e(Fo
-.Pq left guillemet
-.It \e(Fc
-.Pq right guillemet
-.It \e(fo
-.Pq left guilsing
-.It \e(fc
-.Pq right guilsing
-.It \e(rC
-.Pq right brace
-.It \e(lC
-.Pq left brace
-.It \e(ra
-.Pq right angle
-.It \e(la
-.Pq left angle
-.It \e(rB
-.Pq right bracket
-.It \e(lB
-.Pq left bracket
-.It \eq
-.Pq double-quote
-.It \e(lq
-.Pq left double-quote
-.It \e(Lq
-.Pq left double-quote, deprecated
-.It \e(rq
-.Pq right double-quote
-.It \e(Rq
-.Pq right double-quote, deprecated
-.It \e(oq
-.Pq left single-quote
-.It \e(aq
-.Pq right single-quote
-.It \e(Bq
-.Pq right low double-quote
-.It \e(bq
-.Pq right low single-quote
+.Pp
+Punctuation:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(em Ta \(em Ta em-dash
+.It \e(en Ta \(en Ta en-dash
+.It \e(hy Ta \(hy Ta hyphen
+.It \ee Ta \e Ta back-slash
+.It \e. Ta \. Ta period
+.It \e(r! Ta \(r! Ta upside-down exclamation
+.It \e(r? Ta \(r? Ta upside-down question
+.El
+.Pp
+Quotes:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(Bq Ta \(Bq Ta right low double-quote
+.It \e(bq Ta \(bq Ta right low single-quote
+.It \e(lq Ta \(lq Ta left double-quote
+.It \e(rq Ta \(rq Ta right double-quote
+.It \e(oq Ta \(oq Ta left single-quote
+.It \e(cq Ta \(cq Ta right single-quote
+.It \e(aq Ta \(aq Ta apostrophe quote (text)
+.It \e(dq Ta \(dq Ta double quote (text)
+.It \e(Fo Ta \(Fo Ta left guillemet
+.It \e(Fc Ta \(Fc Ta right guillemet
+.It \e(fo Ta \(fo Ta left single guillemet
+.It \e(fc Ta \(fc Ta right single guillemet
+.El
+.Pp
+Brackets:
+.Bl -column "xxbracketrightbtx" Rendered Description -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(lB Ta \(lB Ta left bracket
+.It \e(rB Ta \(rB Ta right bracket
+.It \e(lC Ta \(lC Ta left brace
+.It \e(rC Ta \(rC Ta right brace
+.It \e(la Ta \(la Ta left angle
+.It \e(ra Ta \(ra Ta right angle
+.It \e(bv Ta \(bv Ta brace extension
+.It \e[braceex] Ta \[braceex] Ta brace extension
+.It \e[bracketlefttp] Ta \[bracketlefttp] Ta top-left hooked bracket
+.It \e[bracketleftbt] Ta \[bracketleftbt] Ta bottom-left hooked bracket
+.It \e[bracketleftex] Ta \[bracketleftex] Ta left hooked bracket extension
+.It \e[bracketrighttp] Ta \[bracketrighttp] Ta top-right hooked bracket
+.It \e[bracketrightbt] Ta \[bracketrightbt] Ta bottom-right hooked bracket
+.It \e[bracketrightex] Ta \[bracketrightex] Ta right hooked bracket extension
+.It \e(lt Ta \(lt Ta top-left hooked brace
+.It \e[bracelefttp] Ta \[bracelefttp] Ta top-left hooked brace
+.It \e(lk Ta \(lk Ta mid-left hooked brace
+.It \e[braceleftmid] Ta \[braceleftmid] Ta mid-left hooked brace
+.It \e(lb Ta \(lb Ta bottom-left hooked brace
+.It \e[braceleftbt] Ta \[braceleftbt] Ta bottom-left hooked brace
+.It \e[braceleftex] Ta \[braceleftex] Ta left hooked brace extension
+.It \e(rt Ta \(rt Ta top-left hooked brace
+.It \e[bracerighttp] Ta \[bracerighttp] Ta top-right hooked brace
+.It \e(rk Ta \(rk Ta mid-right hooked brace
+.It \e[bracerightmid] Ta \[bracerightmid] Ta mid-right hooked brace
+.It \e(rb Ta \(rb Ta bottom-right hooked brace
+.It \e[bracerightbt] Ta \[bracerightbt] Ta bottom-right hooked brace
+.It \e[bracerightex] Ta \[bracerightex] Ta right hooked brace extension
+.It \e[parenlefttp] Ta \[parenlefttp] Ta top-left hooked parenthesis
+.It \e[parenleftbt] Ta \[parenleftbt] Ta bottom-left hooked parenthesis
+.It \e[parenleftex] Ta \[parenleftex] Ta left hooked parenthesis extension
+.It \e[parenrighttp] Ta \[parenrighttp] Ta top-right hooked parenthesis
+.It \e[parenrightbt] Ta \[parenrightbt] Ta bottom-right hooked parenthesis
+.It \e[parenrightex] Ta \[parenrightex] Ta right hooked parenthesis extension
+.El
+.Pp
+Arrows:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(<- Ta \(<- Ta left arrow
+.It \e(-> Ta \(-> Ta right arrow
+.It \e(<> Ta \(<> Ta left-right arrow
+.It \e(da Ta \(da Ta down arrow
+.It \e(ua Ta \(ua Ta up arrow
+.It \e(va Ta \(va Ta up-down arrow
+.It \e(lA Ta \(lA Ta left double-arrow
+.It \e(rA Ta \(rA Ta right double-arrow
+.It \e(hA Ta \(hA Ta left-right double-arrow
+.It \e(uA Ta \(uA Ta up double-arrow
+.It \e(dA Ta \(dA Ta down double-arrow
+.It \e(vA Ta \(vA Ta up-down double-arrow
+.It \e(an Ta \(an Ta horizontal arrow extension
.El
-.\" PARAGRAPH
-.Pp
-Indicatives:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(<-
-.Pq left arrow
-.It \e(->
-.Pq right arrow
-.It \e(ua
-.Pq up arrow
-.It \e(da
-.Pq down arrow
-.It \e(<>
-.Pq left-right arrow
-.It \e(lA
-.Pq left double-arrow
-.It \e(rA
-.Pq right double-arrow
-.It \e(uA
-.Pq up double-arrow
-.It \e(dA
-.Pq down double-arrow
-.It \e(hA
-.Pq left-right double-arrow
+.Pp
+Logical:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(AN Ta \(AN Ta logical and
+.It \e(OR Ta \(OR Ta logical or
+.It \e(no Ta \(no Ta logical not
+.It \e[tno] Ta \[tno] Ta logical not (text)
+.It \e(te Ta \(te Ta existential quantifier
+.It \e(fa Ta \(fa Ta universal quantifier
+.It \e(st Ta \(st Ta such that
+.It \e(tf Ta \(tf Ta therefore
+.It \e(3d Ta \(3d Ta therefore
+.It \e(or Ta \(or Ta bitwise or
.El
-.\" PARAGRAPH
.Pp
Mathematical:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(es
-.Pq empty set
-.It \e(ca
-.Pq intersection
-.It \e(cu
-.Pq union
-.It \e(gr
-.Pq gradient
-.It \e(pd
-.Pq partial differential
-.It \e(ap
-.Pq similarity
-.It \e(=)
-.Pq proper superset
-.It \e((=
-.Pq proper subset
-.It \e(eq
-.Pq equals
-.It \e(di
-.Pq division
-.It \e(mu
-.Pq multiplication
-.It \e(pl
-.Pq addition
-.It \e(nm
-.Pq not element
-.It \e(mo
-.Pq element
-.It \e(Im
-.Pq imaginary
-.It \e(Re
-.Pq real
-.It \e(Ah
-.Pq aleph
-.It \e(te
-.Pq existential quantifier
-.It \e(fa
-.Pq universal quantifier
-.It \e(AN
-.Pq logical AND
-.It \e(OR
-.Pq logical OR
-.It \e(no
-.Pq logical NOT
-.It \e(st
-.Pq such that
-.It \e(tf
-.Pq therefore
-.It \e(~~
-.Pq approximate
-.It \e(~=
-.Pq approximately equals
-.It \e(=~
-.Pq congruent
-.It \e(Gt
-.Pq greater-than, deprecated
-.It \e(Lt
-.Pq less-than, deprecated
-.It \e(<=
-.Pq less-than-equal
-.It \e(Le
-.Pq less-than-equal, deprecated
-.It \e(>=
-.Pq greater-than-equal
-.It \e(Ge
-.Pq greater-than-equal
-.It \e(==
-.Pq equal
-.It \e(!=
-.Pq not equal
-.It \e(Ne
-.Pq not equal, deprecated
-.It \e(if
-.Pq infinity
-.It \e(If
-.Pq infinity, deprecated
-.It \e(na
-.Pq NaN , an extension
-.It \e(Na
-.Pq NaN, deprecated
-.It \e(+-
-.Pq plus-minus
-.It \e(Pm
-.Pq plus-minus, deprecated
-.It \e(**
-.Pq asterisk
+.Bl -column "xxcoproductxx" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(pl Ta \(pl Ta plus
+.It \e(mi Ta \(mi Ta minus
+.It \e- Ta \- Ta minus (text)
+.It \e(-+ Ta \(-+ Ta minus-plus
+.It \e(+- Ta \(+- Ta plus-minus
+.It \e[t+-] Ta \[t+-] Ta plus-minus (text)
+.It \e(pc Ta \(pc Ta center-dot
+.It \e(mu Ta \(mu Ta multiply
+.It \e[tmu] Ta \[tmu] Ta multiply (text)
+.It \e(c* Ta \(c* Ta circle-multiply
+.It \e(c+ Ta \(c+ Ta circle-plus
+.It \e(di Ta \(di Ta divide
+.It \e[tdi] Ta \[tdi] Ta divide (text)
+.It \e(f/ Ta \(f/ Ta fraction
+.It \e(** Ta \(** Ta asterisk
+.It \e(<= Ta \(<= Ta less-than-equal
+.It \e(>= Ta \(>= Ta greater-than-equal
+.It \e(<< Ta \(<< Ta much less
+.It \e(>> Ta \(>> Ta much greater
+.It \e(eq Ta \(eq Ta equal
+.It \e(!= Ta \(!= Ta not equal
+.It \e(== Ta \(== Ta equivalent
+.It \e(ne Ta \(ne Ta not equivalent
+.It \e(ap Ta \(ap Ta tilde operator
+.It \e(|= Ta \(|= Ta asymptotically equal
+.It \e(=\(ti Ta \(=~ Ta approximately equal
+.It \e(\(ti\(ti Ta \(~~ Ta almost equal
+.It \e(\(ti= Ta \(~= Ta almost equal
+.It \e(pt Ta \(pt Ta proportionate
+.It \e(es Ta \(es Ta empty set
+.It \e(mo Ta \(mo Ta element
+.It \e(nm Ta \(nm Ta not element
+.It \e(sb Ta \(sb Ta proper subset
+.It \e(nb Ta \(nb Ta not subset
+.It \e(sp Ta \(sp Ta proper superset
+.It \e(nc Ta \(nc Ta not superset
+.It \e(ib Ta \(ib Ta reflexive subset
+.It \e(ip Ta \(ip Ta reflexive superset
+.It \e(ca Ta \(ca Ta intersection
+.It \e(cu Ta \(cu Ta union
+.It \e(/_ Ta \(/_ Ta angle
+.It \e(pp Ta \(pp Ta perpendicular
+.It \e(is Ta \(is Ta integral
+.It \e[integral] Ta \[integral] Ta integral
+.It \e[sum] Ta \[sum] Ta summation
+.It \e[product] Ta \[product] Ta product
+.It \e[coproduct] Ta \[coproduct] Ta coproduct
+.It \e(gr Ta \(gr Ta gradient
+.It \e(sr Ta \(sr Ta square root
+.It \e[sqrt] Ta \[sqrt] Ta square root
+.It \e(lc Ta \(lc Ta left-ceiling
+.It \e(rc Ta \(rc Ta right-ceiling
+.It \e(lf Ta \(lf Ta left-floor
+.It \e(rf Ta \(rf Ta right-floor
+.It \e(if Ta \(if Ta infinity
+.It \e(Ah Ta \(Ah Ta aleph
+.It \e(Im Ta \(Im Ta imaginary
+.It \e(Re Ta \(Re Ta real
+.It \e(wp Ta \(wp Ta Weierstrass p
+.It \e(pd Ta \(pd Ta partial differential
+.It \e(-h Ta \(-h Ta Planck constant over 2\(*p
+.It \e[hbar] Ta \[hbar] Ta Planck constant over 2\(*p
+.It \e(12 Ta \(12 Ta one-half
+.It \e(14 Ta \(14 Ta one-fourth
+.It \e(34 Ta \(34 Ta three-fourths
+.It \e(18 Ta \(18 Ta one-eighth
+.It \e(38 Ta \(38 Ta three-eighths
+.It \e(58 Ta \(58 Ta five-eighths
+.It \e(78 Ta \(78 Ta seven-eighths
+.It \e(S1 Ta \(S1 Ta superscript 1
+.It \e(S2 Ta \(S2 Ta superscript 2
+.It \e(S3 Ta \(S3 Ta superscript 3
.El
-.\" PARAGRAPH
.Pp
Ligatures:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(ss
-.Pq German eszett
-.It \e(AE
-.Pq upper-case AE
-.It \e(ae
-.Pq lower-case AE
-.It \e(OE
-.Pq upper-case OE
-.It \e(oe
-.Pq lower-case OE
-.It \e(ff
-.Pq ff ligature
-.It \e(fi
-.Pq fi ligature
-.It \e(fl
-.Pq fl ligature
-.It \e(Fi
-.Pq ffi ligature
-.It \e(Fl
-.Pq ffl ligature
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(ff Ta \(ff Ta ff ligature
+.It \e(fi Ta \(fi Ta fi ligature
+.It \e(fl Ta \(fl Ta fl ligature
+.It \e(Fi Ta \(Fi Ta ffi ligature
+.It \e(Fl Ta \(Fl Ta ffl ligature
+.It \e(AE Ta \(AE Ta AE
+.It \e(ae Ta \(ae Ta ae
+.It \e(OE Ta \(OE Ta OE
+.It \e(oe Ta \(oe Ta oe
+.It \e(ss Ta \(ss Ta German eszett
+.It \e(IJ Ta \(IJ Ta IJ ligature
+.It \e(ij Ta \(ij Ta ij ligature
+.El
+.Pp
+Accents:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(a" Ta \(a" Ta Hungarian umlaut
+.It \e(a- Ta \(a- Ta macron
+.It \e(a. Ta \(a. Ta dotted
+.It \e(a^ Ta \(a^ Ta circumflex
+.It \e(aa Ta \(aa Ta acute
+.It \e\(aq Ta \' Ta acute
+.It \e(ga Ta \(ga Ta grave
+.It \e\(ga Ta \` Ta grave
+.It \e(ab Ta \(ab Ta breve
+.It \e(ac Ta \(ac Ta cedilla
+.It \e(ad Ta \(ad Ta dieresis
+.It \e(ah Ta \(ah Ta caron
+.It \e(ao Ta \(ao Ta ring
+.It \e(a\(ti Ta \(a~ Ta tilde
+.It \e(ho Ta \(ho Ta ogonek
+.It \e(ha Ta \(ha Ta hat (text)
+.It \e(ti Ta \(ti Ta tilde (text)
+.El
+.Pp
+Accented letters:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(\(aqA Ta \('A Ta acute A
+.It \e(\(aqE Ta \('E Ta acute E
+.It \e(\(aqI Ta \('I Ta acute I
+.It \e(\(aqO Ta \('O Ta acute O
+.It \e(\(aqU Ta \('U Ta acute U
+.It \e(\(aqa Ta \('a Ta acute a
+.It \e(\(aqe Ta \('e Ta acute e
+.It \e(\(aqi Ta \('i Ta acute i
+.It \e(\(aqo Ta \('o Ta acute o
+.It \e(\(aqu Ta \('u Ta acute u
+.It \e(\(gaA Ta \(`A Ta grave A
+.It \e(\(gaE Ta \(`E Ta grave E
+.It \e(\(gaI Ta \(`I Ta grave I
+.It \e(\(gaO Ta \(`O Ta grave O
+.It \e(\(gaU Ta \(`U Ta grave U
+.It \e(\(gaa Ta \(`a Ta grave a
+.It \e(\(gae Ta \(`e Ta grave e
+.It \e(\(gai Ta \(`i Ta grave i
+.It \e(\(gao Ta \(`i Ta grave o
+.It \e(\(gau Ta \(`u Ta grave u
+.It \e(\(tiA Ta \(~A Ta tilde A
+.It \e(\(tiN Ta \(~N Ta tilde N
+.It \e(\(tiO Ta \(~O Ta tilde O
+.It \e(\(tia Ta \(~a Ta tilde a
+.It \e(\(tin Ta \(~n Ta tilde n
+.It \e(\(tio Ta \(~o Ta tilde o
+.It \e(:A Ta \(:A Ta dieresis A
+.It \e(:E Ta \(:E Ta dieresis E
+.It \e(:I Ta \(:I Ta dieresis I
+.It \e(:O Ta \(:O Ta dieresis O
+.It \e(:U Ta \(:U Ta dieresis U
+.It \e(:a Ta \(:a Ta dieresis a
+.It \e(:e Ta \(:e Ta dieresis e
+.It \e(:i Ta \(:i Ta dieresis i
+.It \e(:o Ta \(:o Ta dieresis o
+.It \e(:u Ta \(:u Ta dieresis u
+.It \e(:y Ta \(:y Ta dieresis y
+.It \e(^A Ta \(^A Ta circumflex A
+.It \e(^E Ta \(^E Ta circumflex E
+.It \e(^I Ta \(^I Ta circumflex I
+.It \e(^O Ta \(^O Ta circumflex O
+.It \e(^U Ta \(^U Ta circumflex U
+.It \e(^a Ta \(^a Ta circumflex a
+.It \e(^e Ta \(^e Ta circumflex e
+.It \e(^i Ta \(^i Ta circumflex i
+.It \e(^o Ta \(^o Ta circumflex o
+.It \e(^u Ta \(^u Ta circumflex u
+.It \e(,C Ta \(,C Ta cedilla C
+.It \e(,c Ta \(,c Ta cedilla c
+.It \e(/L Ta \(/L Ta stroke L
+.It \e(/l Ta \(/l Ta stroke l
+.It \e(/O Ta \(/O Ta stroke O
+.It \e(/o Ta \(/o Ta stroke o
+.It \e(oA Ta \(oA Ta ring A
+.It \e(oa Ta \(oa Ta ring a
+.El
+.Pp
+Special letters:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(-D Ta \(-D Ta Eth
+.It \e(Sd Ta \(Sd Ta eth
+.It \e(TP Ta \(TP Ta Thorn
+.It \e(Tp Ta \(Tp Ta thorn
+.It \e(.i Ta \(.i Ta dotless i
+.It \e(.j Ta \(.j Ta dotless j
+.El
+.Pp
+Currency:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(Do Ta \(Do Ta dollar
+.It \e(ct Ta \(ct Ta cent
+.It \e(Eu Ta \(Eu Ta Euro symbol
+.It \e(eu Ta \(eu Ta Euro symbol
+.It \e(Ye Ta \(Ye Ta yen
+.It \e(Po Ta \(Po Ta pound
+.It \e(Cs Ta \(Cs Ta Scandinavian
+.It \e(Fn Ta \(Fn Ta florin
.El
-.\" PARAGRAPH
-.Pp
-Diacritics and letters:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(ga
-.Pq grave accent
-.It \e(aa
-.Pq accute accent
-.It \e(a"
-.Pq umlaut accent
-.It \e(ad
-.Pq dieresis accent
-.It \e(a~
-.Pq tilde accent
-.It \e(a^
-.Pq circumflex accent
-.It \e(ac
-.Pq cedilla accent
-.It \e(ad
-.Pq dieresis accent
-.It \e(ah
-.Pq caron accent
-.It \e(ao
-.Pq ring accent
-.It \e(ho
-.Pq hook accent
-.It \e(ab
-.Pq breve accent
-.It \e(a-
-.Pq macron accent
-.It \e(-D
-.Pq upper-case eth
-.It \e(Sd
-.Pq lower-case eth
-.It \e(TP
-.Pq upper-case thorn
-.It \e(Tp
-.Pq lower-case thorn
-.It \e('A
-.Pq upper-case acute A
-.It \e('E
-.Pq upper-case acute E
-.It \e('I
-.Pq upper-case acute I
-.It \e('O
-.Pq upper-case acute O
-.It \e('U
-.Pq upper-case acute U
-.It \e('a
-.Pq lower-case acute a
-.It \e('e
-.Pq lower-case acute e
-.It \e('i
-.Pq lower-case acute i
-.It \e('o
-.Pq lower-case acute o
-.It \e('u
-.Pq lower-case acute u
-.It \e(`A
-.Pq upper-case grave A
-.It \e(`E
-.Pq upper-case grave E
-.It \e(`I
-.Pq upper-case grave I
-.It \e(`O
-.Pq upper-case grave O
-.It \e(`U
-.Pq upper-case grave U
-.It \e(`a
-.Pq lower-case grave a
-.It \e(`e
-.Pq lower-case grave e
-.It \e(`i
-.Pq lower-case grave i
-.It \e(`o
-.Pq lower-case grave o
-.It \e(`u
-.Pq lower-case grave u
-.It \e(~A
-.Pq upper-case tilde A
-.It \e(~N
-.Pq upper-case tilde N
-.It \e(~O
-.Pq upper-case tilde O
-.It \e(~a
-.Pq lower-case tilde a
-.It \e(~n
-.Pq lower-case tilde n
-.It \e(~o
-.Pq lower-case tilde o
-.It \e(:A
-.Pq upper-case dieresis A
-.It \e(:E
-.Pq upper-case dieresis E
-.It \e(:I
-.Pq upper-case dieresis I
-.It \e(:O
-.Pq upper-case dieresis O
-.It \e(:U
-.Pq upper-case dieresis U
-.It \e(:a
-.Pq lower-case dieresis a
-.It \e(:e
-.Pq lower-case dieresis e
-.It \e(:i
-.Pq lower-case dieresis i
-.It \e(:o
-.Pq lower-case dieresis o
-.It \e(:u
-.Pq lower-case dieresis u
-.It \e(:y
-.Pq lower-case dieresis y
-.It \e(^A
-.Pq upper-case circumflex A
-.It \e(^E
-.Pq upper-case circumflex E
-.It \e(^I
-.Pq upper-case circumflex I
-.It \e(^O
-.Pq upper-case circumflex O
-.It \e(^U
-.Pq upper-case circumflex U
-.It \e(^a
-.Pq lower-case circumflex a
-.It \e(^e
-.Pq lower-case circumflex e
-.It \e(^i
-.Pq lower-case circumflex i
-.It \e(^o
-.Pq lower-case circumflex o
-.It \e(^u
-.Pq lower-case circumflex u
-.It \e(,C
-.Pq upper-case cedilla C
-.It \e(,c
-.Pq lower-case cedilla c
-.It \e(/L
-.Pq upper-case stroke L
-.It \e(/l
-.Pq lower-case stroke l
-.It \e(/O
-.Pq upper-case stroke O
-.It \e(/o
-.Pq lower-case stroke o
-.It \e(oA
-.Pq upper-case ring A
-.It \e(oa
-.Pq lower-case ring a
+.Pp
+Units:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(de Ta \(de Ta degree
+.It \e(%0 Ta \(%0 Ta per-thousand
+.It \e(fm Ta \(fm Ta minute
+.It \e(sd Ta \(sd Ta second
+.It \e(mc Ta \(mc Ta micro
+.It \e(Of Ta \(Of Ta Spanish female ordinal
+.It \e(Om Ta \(Om Ta Spanish masculine ordinal
+.El
+.Pp
+Greek letters:
+.Bl -column "Input" "Rendered" "Description" -offset indent -compact
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e(*A Ta \(*A Ta Alpha
+.It \e(*B Ta \(*B Ta Beta
+.It \e(*G Ta \(*G Ta Gamma
+.It \e(*D Ta \(*D Ta Delta
+.It \e(*E Ta \(*E Ta Epsilon
+.It \e(*Z Ta \(*Z Ta Zeta
+.It \e(*Y Ta \(*Y Ta Eta
+.It \e(*H Ta \(*H Ta Theta
+.It \e(*I Ta \(*I Ta Iota
+.It \e(*K Ta \(*K Ta Kappa
+.It \e(*L Ta \(*L Ta Lambda
+.It \e(*M Ta \(*M Ta Mu
+.It \e(*N Ta \(*N Ta Nu
+.It \e(*C Ta \(*C Ta Xi
+.It \e(*O Ta \(*O Ta Omicron
+.It \e(*P Ta \(*P Ta Pi
+.It \e(*R Ta \(*R Ta Rho
+.It \e(*S Ta \(*S Ta Sigma
+.It \e(*T Ta \(*T Ta Tau
+.It \e(*U Ta \(*U Ta Upsilon
+.It \e(*F Ta \(*F Ta Phi
+.It \e(*X Ta \(*X Ta Chi
+.It \e(*Q Ta \(*Q Ta Psi
+.It \e(*W Ta \(*W Ta Omega
+.It \e(*a Ta \(*a Ta alpha
+.It \e(*b Ta \(*b Ta beta
+.It \e(*g Ta \(*g Ta gamma
+.It \e(*d Ta \(*d Ta delta
+.It \e(*e Ta \(*e Ta epsilon
+.It \e(*z Ta \(*z Ta zeta
+.It \e(*y Ta \(*y Ta eta
+.It \e(*h Ta \(*h Ta theta
+.It \e(*i Ta \(*i Ta iota
+.It \e(*k Ta \(*k Ta kappa
+.It \e(*l Ta \(*l Ta lambda
+.It \e(*m Ta \(*m Ta mu
+.It \e(*n Ta \(*n Ta nu
+.It \e(*c Ta \(*c Ta xi
+.It \e(*o Ta \(*o Ta omicron
+.It \e(*p Ta \(*p Ta pi
+.It \e(*r Ta \(*r Ta rho
+.It \e(*s Ta \(*s Ta sigma
+.It \e(*t Ta \(*t Ta tau
+.It \e(*u Ta \(*u Ta upsilon
+.It \e(*f Ta \(*f Ta phi
+.It \e(*x Ta \(*x Ta chi
+.It \e(*q Ta \(*q Ta psi
+.It \e(*w Ta \(*w Ta omega
+.It \e(+h Ta \(+h Ta theta variant
+.It \e(+f Ta \(+f Ta phi variant
+.It \e(+p Ta \(+p Ta pi variant
+.It \e(+e Ta \(+e Ta epsilon variant
+.It \e(ts Ta \(ts Ta sigma terminal
.El
-.\" PARAGRAPH
-.Pp
-Monetary:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(Cs
-.Pq Scandinavian
-.It \e(Do
-.Pq dollar
-.It \e(Po
-.Pq pound
-.It \e(Ye
-.Pq yen
-.It \e(Fn
-.Pq florin
-.It \e(ct
-.Pq cent
+.Sh PREDEFINED STRINGS
+Predefined strings are inherited from the macro packages of historical
+troff implementations.
+They are
+.Em not recommended
+for use, as they differ across implementations.
+Manuals using these predefined strings are almost certainly not
+portable.
+.Pp
+Their syntax is similar to special characters, using
+.Sq \e*X
+.Pq for a one-character escape ,
+.Sq \e*(XX
+.Pq two-character ,
+and
+.Sq \e*[N]
+.Pq N-character .
+For details, see the
+.Em Predefined Strings
+subsection of the
+.Xr roff 7
+manual.
+.Bl -column "Input" "Rendered" "Description" -offset indent
+.It Em Input Ta Em Rendered Ta Em Description
+.It \e*(Ba Ta \*(Ba Ta vertical bar
+.It \e*(Ne Ta \*(Ne Ta not equal
+.It \e*(Ge Ta \*(Ge Ta greater-than-equal
+.It \e*(Le Ta \*(Le Ta less-than-equal
+.It \e*(Gt Ta \*(Gt Ta greater-than
+.It \e*(Lt Ta \*(Lt Ta less-than
+.It \e*(Pm Ta \*(Pm Ta plus-minus
+.It \e*(If Ta \*(If Ta infinity
+.It \e*(Pi Ta \*(Pi Ta pi
+.It \e*(Na Ta \*(Na Ta NaN
+.It \e*(Am Ta \*(Am Ta ampersand
+.It \e*R Ta \*R Ta restricted mark
+.It \e*(Tm Ta \*(Tm Ta trade mark
+.It \e*q Ta \*q Ta double-quote
+.It \e*(Rq Ta \*(Rq Ta right-double-quote
+.It \e*(Lq Ta \*(Lq Ta left-double-quote
+.It \e*(lp Ta \*(lp Ta right-parenthesis
+.It \e*(rp Ta \*(rp Ta left-parenthesis
+.It \e*(lq Ta \*(lq Ta left double-quote
+.It \e*(rq Ta \*(rq Ta right double-quote
+.It \e*(ua Ta \*(ua Ta up arrow
+.It \e*(va Ta \*(va Ta up-down arrow
+.It \e*(<= Ta \*(<= Ta less-than-equal
+.It \e*(>= Ta \*(>= Ta greater-than-equal
+.It \e*(aa Ta \*(aa Ta acute
+.It \e*(ga Ta \*(ga Ta grave
+.It \e*(Px Ta \*(Px Ta POSIX standard name
+.It \e*(Ai Ta \*(Ai Ta ANSI standard name
.El
-.\" PARAGRAPH
-.Pp
-Special symbols:
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e0
-.Pq white-space
-.It \e(de
-.Pq degree
-.It \e(ps
-.Pq paragraph
-.It \e(sc
-.Pq section
-.It \e(dg
-.Pq dagger
-.It \e(dd
-.Pq double dagger
-.It \e(ci
-.Pq circle
-.It \e(ba
-.Pq bar
-.It \e(bb
-.Pq broken bar
-.It \e(Ba
-.Pq bar, deprecated
-.It \e(co
-.Pq copyright
-.It \e(rg
-.Pq registered
-.It \e(tm
-.Pq trademarked
-.It \e&
-.Pq non-breaking space
-.It \ee
-.Pq escape
-.It \e(Am
-.Pq ampersand, deprecated
-.El
-.\" SECTION
+.Sh UNICODE CHARACTERS
+The escape sequences
+.Pp
+.Dl \e[uXXXX] and \eC\(aquXXXX\(aq
+.Pp
+are interpreted as Unicode codepoints.
+The codepoint must be in the range above U+0080 and less than U+10FFFF.
+For compatibility, the hexadecimal digits
+.Sq A
+to
+.Sq F
+must be given as uppercase characters,
+and points must be zero-padded to four characters; if
+greater than four characters, no zero padding is allowed.
+Unicode surrogates are not allowed.
+.Sh NUMBERED CHARACTERS
+For backward compatibility with existing manuals,
+.Xr mandoc 1
+also supports the
+.Pp
+.Dl \eN\(aq Ns Ar number Ns \(aq
+.Pp
+escape sequence, inserting the character
+.Ar number
+from the current character set into the output.
+Of course, this is inherently non-portable and is already marked
+as deprecated in the Heirloom roff manual.
+For example, do not use \eN\(aq34\(aq, use \e(dq, or even the plain
+.Sq \(dq
+character where possible.
.Sh COMPATIBILITY
-This section documents compatibility of
-.Nm
-with older or existing versions of
-.Xr groff 1 :
-.Pp
-.Bl -tag -width 12n -offset "XXXX" -compact
-.It \e(ss
-Renders differently in
-.Fl T Ns Ar ascii
-mode.
+This section documents compatibility between mandoc and other
+troff implementations, at this time limited to GNU troff
+.Pq Qq groff .
+.Pp
+.Bl -dash -compact
+.It
+The \eN\(aq\(aq escape sequence is limited to printable characters; in
+groff, it accepts arbitrary character numbers.
+.It
+In
+.Fl T Ns Cm ascii ,
+the
+\e(ss, \e(nm, \e(nb, \e(nc, \e(ib, \e(ip, \e(pp, \e[sum], \e[product],
+\e[coproduct], \e(gr, \e(-h, and \e(a. special characters render
+differently between mandoc and groff.
+.It
+In
+.Fl T Ns Cm html ,
+the \e(\(ti=, \e(nb, and \e(nc special characters render differently
+between mandoc and groff.
+.It
+The
+.Fl T Ns Cm ps
+and
+.Fl T Ns Cm pdf
+modes format like
+.Fl T Ns Cm ascii
+instead of rendering glyphs as in groff.
+.It
+The \e[radicalex], \e[sqrtex], and \e(ru special characters have been omitted
+from mandoc either because they are poorly documented or they have no
+known representation.
.El
-.\" SECTION
.Sh SEE ALSO
-.Xr mandoc 1
-.\" SECTION
+.Xr mandoc 1 ,
+.Xr man 7 ,
+.Xr mdoc 7 ,
+.Xr roff 7
.Sh AUTHORS
The
.Nm
-utility was written by
-.An Kristaps Dzonsons Aq kristaps@openbsd.org .
+manual page was written by
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .
+.Sh CAVEATS
+The predefined string
+.Sq \e*(Ba
+mimics the behaviour of the
+.Sq \&|
+character in
+.Xr mdoc 7 ;
+thus, if you wish to render a vertical bar with no side effects, use
+the
+.Sq \e(ba
+escape.
git.ckatri.com / mandoc.git / blobdiff