.\" $Id$
.\"
.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@bsd.lv>
.\"
.\" 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.
.\"
.\" 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 $Mdocdate$
.Dt MANDOC_CHAR 7
.Os
.Sh NAME
.Nm mandoc_char
.Nd mandoc special characters
.Sh DESCRIPTION
This page documents the special characters and predefined strings accepted by
.Xr mandoc 1
to format
.Xr mdoc 7
and
.Xr man 7
documents.
.Pp
Both
.Xr mdoc 7
and
.Xr man 7
encode special characters with
.Sq \eX
.Pq for a one-character escape ,
.Sq \e(XX
.Pq two-character ,
and
.Sq \e[N]
.Pq N-character .
One may generalise
.Sq \e(XX
as
.Sq \e[XX]
and
.Sq \eX
as
.Sq \e[X] .
Predefined strings are functionally 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 .
One may generalise
.Sq \e*(XX
as
.Sq \e*[XX]
and
.Sq \e*X
as
.Sq \e*[X] .
.Pp
Note that each output mode will have a different rendering of the
characters.
It's guaranteed that each input symbol will correspond to a
(more or less) meaningful output rendering, regardless the mode.
.Sh SPECIAL CHARACTERS
These are the preferred input symbols for producing special characters.
.Pp
Spacing:
.Bl -column -compact -offset indent "Input" "Description"
.It Em Input Ta Em Description
.It \e~ Ta non-breaking, non-collapsing space
.It \e Ta breaking, non-collapsing n-width space
.It \e^ Ta zero-width space
.It \e% Ta zero-width space
.It \e& Ta zero-width space
.It \e| Ta zero-width space
.It \e0 Ta breaking, non-collapsing digit-width space
.It \ec Ta removes any trailing space (if applicable)
.El
.Pp
Lines:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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(rl Ta \(rl 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 -compact -offset indent "Input" "Rendered" "Description"
.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
.El
.Pp
Legal symbols:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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
.Pp
Punctuation:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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 -compact -offset indent "Input" "Rendered" "Description"
.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 -compact -offset indent "xxbracketrightbpx" Rendered Description
.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[bracketleftbp] Ta \[bracketleftbp] 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[bracketrightbp] Ta \[bracketrightbp] 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[braceleftbp] Ta \[braceleftbp] 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[bracerightbp] Ta \[bracerightbp] 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[parenleftbp] Ta \[parenleftbp] 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[parenrightbp] Ta \[parenrightbp] Ta bottom-right hooked parenthesis
.It \e[parenrightex] Ta \[parenrightex] Ta right hooked parenthesis extension
.El
.Pp
Arrows:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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
.El
.Pp
Logical:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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
.Pp
Mathematical:
.Bl -column -compact -offset indent "xxcoproductxx" "Rendered" "Description"
.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 centre-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(=~ Ta \(=~ Ta congruent
.It \e(-~ Ta \(-~ Ta asymptotically congruent
.It \e(ap Ta \(ap Ta asymptotically similar
.It \e(~~ Ta \(~~ Ta approximately similar
.It \e(~= Ta \(~= Ta approximately 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(pd Ta \(pd Ta partial differential
.It \e(-h Ta \(-h 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
.El
.Pp
Ligatures:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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 -compact -offset indent "Input" "Rendered" "Description"
.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' Ta \' Ta acute
.It \e(ga Ta \(ga Ta grave
.It \e` 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~ 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 -compact -offset indent "Input" "Rendered" "Description"
.It Em Input Ta Em Rendered Ta Em Description
.It \e('A Ta \('A Ta acute A
.It \e('E Ta \('E Ta acute E
.It \e('I Ta \('I Ta acute I
.It \e('O Ta \('O Ta acute O
.It \e('U Ta \('U Ta acute U
.It \e('a Ta \('a Ta acute a
.It \e('e Ta \('e Ta acute e
.It \e('i Ta \('i Ta acute i
.It \e('o Ta \('o Ta acute o
.It \e('u Ta \('u Ta acute u
.It \e(`A Ta \(`A Ta grave A
.It \e(`E Ta \(`E Ta grave E
.It \e(`I Ta \(`I Ta grave I
.It \e(`O Ta \(`O Ta grave O
.It \e(`U Ta \(`U Ta grave U
.It \e(`a Ta \(`a Ta grave a
.It \e(`e Ta \(`e Ta grave e
.It \e(`i Ta \(`i Ta grave i
.It \e(`o Ta \(`i Ta grave o
.It \e(`u Ta \(`u Ta grave u
.It \e(~A Ta \(~A Ta tilde A
.It \e(~N Ta \(~N Ta tilde N
.It \e(~O Ta \(~O Ta tilde O
.It \e(~a Ta \(~a Ta tilde a
.It \e(~n Ta \(~n Ta tilde n
.It \e(~o 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 -compact -offset indent "Input" "Rendered" "Description"
.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 -compact -offset indent "Input" "Rendered" "Description"
.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
.Pp
Units:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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
.El
.Pp
Greek letters:
.Bl -column -compact -offset indent "Input" "Rendered" "Description"
.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
.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.
.Bl -column -offset indent "Input" "Rendered" "Description"
.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
.Sh UNICODE CHARACTERS
The escape sequence
.Pp
.Dl \e[uXXXX]
.Pp
is interpreted as a Unicode codepoint.
The codepoint must be in the range above U+0080 and less than U+10FFFF.
For compatibility, points must be zero-padded to four characters; if
greater than four characters, no zero padding is allowed.
Unicode surrogates are not allowed.
.\" .Pp
.\" Unicode glyphs attenuate to the
.\" .Sq \&?
.\" character if invalid or not rendered by current output media.
.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'34', use \e(dq, or even the plain
.Sq \(dq
character where possible.
.Sh COMPATIBILITY
This section documents compatibility between mandoc and other 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
and
.Fl T Ns Cm xhtml ,
the \e(~=, \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
.Sh SEE ALSO
.Xr mandoc 1
.Sh AUTHORS
The
.Nm
manual page was written by
.An Kristaps Dzonsons ,
.Mt kristaps@bsd.lv .
.Sh CAVEATS
The
.Sq \e*(Ba
escape 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.
