.\"	$Id$
.\"
.\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>
.\"
.\" 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 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.
.
.Ss ASCII output
Formatting documents with ASCII output results in a 7-bit ASCII
approximation of zero or more characters, for example, the
.Dq aleph
character
.Sq \e(Ah
will render as
.Sq N .
Approximations are a best-effort, and naturally some clarity will be lost.
.
.Ss HTML output
The HTML output mode uses decimal-encoded UTF-8 for sequences, for
example, the
.Dq aleph
character
.Sq \e(Ah
will render as
.Sq &#8501; .
.
.
.Sh SPECIAL CHARACTERS
These are the preferred input symbols for producing special characters.
.
.Pp
Spacing:
.Bl -column -compact -offset indent 10m 20m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 \e\e     Ta \\          Ta back-slash
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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
.El
.
.Pp
Ligatures:
.Bl -column -compact -offset indent 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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 10m 10m 10m
.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
These are not recommended for use, as they differ across
implementations:
.
.Pp
.Bl -column -compact -offset indent 10m 10m 10m
.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
.El
.
.
.Sh COMPATIBILITY
This section documents compatibility of
.Nm
with older or existing versions of
.Xr groff 1 .
.
.Pp
The following render differently in
.Fl T Ns Ar ascii
output mode:
.Bd -ragged -offset indent
\e(ss, \e(nm, \e(nb, \e(nc, \e(ib, \e(ip, \e(pp, \e[sum], \e[product],
\e[coproduct], \e(gr, \e(-h, \e(a.
.Ed
.
.Pp
The following render differently in
.Fl T Ns Ar html
output mode:
.Bd -ragged -offset indent
\e(~=, \e(nb, \e(nc
.Ed
.
.Pp
Finally, the following have been omitted by being poorly documented or
having no known representation:
.Bd -ragged -offset indent
\e[radicalex], \e[sqrtex], \e(ru
.Ed
.
.
.Sh SEE ALSO
.Xr mandoc 1
.
.
.Sh STANDARDS
.Rs
.%A The Unicode Consortium
.%T The Unicode Standard: Worldwide Character Encoding, Version 5.2
.%D 1991
.Re
.Rs
.%A W3C
.%T HTML 4.01 Specification
.%D December, 1999
.Re
.
.
.Sh AUTHORS
The
.Nm
utility was written by 
.An Kristaps Dzonsons Aq kristaps@kth.se .