Provided by: groff_1.23.0-3build2_amd64 bug

Name

       groff_char - GNU roff special character and glyph repertoire

Description

       The  GNU roff typesetting system has a large glyph repertoire suitable for production of varied literary,
       professional, technical, and mathematical documents.  groff  works  with  characters;  an  output  device
       renders  glyphs.   groff's input character set is restricted to that defined by the standards ISO Latin-1
       (ISO 8859-1) and CCSID “code page” 1047 (an  EBCDIC  arrangement  of  Latin-1).   For  ease  of  document
       maintenance  in  UTF-8  environments,  it is advisable to use only the Unicode basic Latin code points, a
       subset of all of the foregoing historically referred to as US-ASCII, which has only 94 visible, printable
       code points.  In groff, these are termed ordinary characters.  Often, many more are desired in output.

       AT&T  troff  in  the  1970s faced a similar problem: the available typesetter's glyph repertoire differed
       from that of the computers that controlled it.  troff's solution was a form of escape sequence known as a
       special  character to access several dozen additional glyphs available in the fonts prepared for mounting
       in the phototypesetter.  These glyphs were mapped onto  a  two-character  name  space  for  a  degree  of
       mnemonic  convenience;  for  example, the escape sequence \(aa encoded an acute accent and \(sc a section
       sign.

       groff has lifted historical roff limitations on  special  character  name  lengths,  but  recognizes  and
       retains  compatibility  with the historical names.  groff expands the lexicon of glyphs available by name
       and permits users to define their own special character escape sequences with the char request.   Special
       character  names  are  groff identifiers; see section “Identifiers” in groff(7).  Our discussion uses the
       terms “glyph name” and “special character name” interchangeably; we assume no character  translations  or
       redefinitions.

       This  document lists all of the glyph names predefined by groff's font description files and presents the
       systematic notation by which it enables access to arbitrary  Unicode  code  points  and  construction  of
       composite  glyphs.   Glyphs listed may be unavailable, or may vary in appearance, depending on the output
       device and font chosen when the page was formatted.  This page was rendered for device utf8 using font R.

       A few escape sequences that are not groff  special  characters  also  produce  glyphs;  these  exist  for
       syntactical  or  historical reasons.  \', \`, \-, and \_ are translated on input to the special character
       escape sequences \[aa], \[ga], \[-], and \[ul], respectively.  Others include \\, \. (backslash-dot), and
       \e; see groff(7).  A small number of special characters represent glyphs that are not encoded in Unicode;
       examples include the baseline rule \[ru] and the Bell System logo \[bs].

       In groff, you can test output device support for any character (ordinary or special) with the conditional
       expression operator “c”.
              .ie c \[bs] \{Welcome to the \[bs] Bell System;
              did you get the Wehrmacht helmet or the Death Star?\}
              .el No Bell System logo.

       For  brevity  in the remainder of this document, we shall refer to systems conforming to the ISO 646:1991
       IRV, ISO 8859, or ISO 10646  (“Unicode”)  character  encoding  standards  as  “ISO”  systems,  and  those
       employing IBM code page 1047 as “EBCDIC” systems.  That said, EBCDIC systems that support groff are known
       to also support UTF-8.

       While groff accepts eight-bit encoded input, not all such  code  points  are  valid  as  input.   On  ISO
       platforms, character codes 0, 11, 13–31, and 128–159 are invalid.  (This is all C0 and C1 controls except
       for SOH through LF [Control+A to Control+J], and FF [Control+L].)   On  EBCDIC  platforms,  0,  8–9,  11,
       13–20,  23–31, and 48–63 are invalid.  Some of these code points are used by groff for internal purposes,
       which is one reason it does not support UTF-8 natively.

   Fundamental character set
       The ordinary characters catalogued above, plus the space, tab, newline, and leader (Control+A), form  the
       fundamental character set for groff input; anything in the language, even over one million code points in
       Unicode, can be expressed using it.  On ISO systems, code points in the range 33–126  comprise  a  common
       set  of  printable  glyphs  in  all  of  the aforementioned ISO character encoding standards.  It is this
       character set and (with some noteworthy exceptions) the corresponding glyph  repertoire  for  which  AT&T
       troff  was  implemented.   On  EBCDIC  systems, printable characters are in the range 66–201 and 203–254;
       those without counterparts in the ISO range 33–126 are discussed in the next subsection.

       All of the following characters map to glyphs as you would expect.

                              ┌──────────────────────────────────────────────────────────┐
                              │! # $ % & ( ) * + , . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ │
                              │A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ ] _ │
                              │a b c d e f g h i j k l m n o p q r s t u v w x y z { | } │
--

Glyph tables

       In this section, groff's glyph name repertoire is presented in tabular form.  The meanings of the columns
       are as follows.

       Output  shows the glyph as it appears on the device used to render this document; although it can have  a
               notably  different  shape  on  other  devices  (and  is  subject to user-directed translation and
               replacement), groff attempts reasonable equivalency on all output devices.

       Input   shows the groff character (ordinary or special) that normally  produces  the  glyph.   Some  code
               points have multiple glyph names.

       Unicode is  the  code point notation for the glyph or combining glyph sequence as described in subsection
               “Special character escape forms” above.  It corresponds to  the  standard  notation  for  Unicode
               short identifiers such that groff's unnnn is equivalent to Unicode's U+nnnn.

       Notes   describes the glyph, elucidating the mnemonic value of the glyph name where possible.

               A  plus  sign “+” indicates that the glyph name appears in the AT&T troff user's manual, CSTR #54
               (1992 revision).  When using the AT&T special character syntax \(xx, widespread  portability  can
               be expected from such names.

               Entries  marked with “***” denote glyphs used for mathematical purposes.  On typesetting devices,
               such glyphs are typically drawn from a special font (see groff_font(5)).  Often, such glyphs lack
               bold  or italic style forms or have metrics that look incongruous in ordinary prose.  A few which
               are not uncommon in running text have “text variants”, which should work better in that  context.
               Conversely,  a  handful  of  glyphs  that  are normally drawn from a text font may be required in
               mathematical equations.  Both sets of exceptions are  noted  in  the  tables  where  they  appear
               (“Logical symbols” and “Mathematical symbols”).

   Basic Latin
       Apart  from  basic Latin characters with special mappings, described in subsection “Fundamental character
       set” above, a few others in that range have special character glyph names.  These were defined  for  ease
       of  input  on  non-U.S.  keyboards lacking keycaps for them, or for symmetry with other special character
       glyph names serving a similar purpose.

       The vertical bar is overloaded; the \[ba]  and  \[or]  escape  sequences  may  render  differently.   See
       subsection  “Mathematical  symbols”  below  for  special  variants  of  the plus, minus, and equals signs
       normally drawn from this range.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       "        \[dq]   u0022     neutral double quote
       #        \[sh]   u0023     number sign
       $        \[Do]   u0024     dollar sign
       '        \[aq]   u0027     apostrophe, neutral single quote
       /        \[sl]   u002F     slash, solidus +
       @        \[at]   u0040     at sign
       [        \[lB]   u005B     left square bracket
       \        \[rs]   u005C     reverse solidus
       ]        \[rB]   u005D     right square bracket
       ^        \[ha]   u005E     circumflex, caret, “hat”
       {        \[lC]   u007B     left brace
       |        |       u007C     bar
       |        \[ba]   u007C     bar
       |        \[or]   u007C     bitwise or +
       }        \[rC]   u007D     right brace
       ~        \[ti]   u007E     tilde

   Supplementary Latin letters
       Historically, \[ss] could be considered a ligature of “sz”.  An uppercase form is available as  \[u1E9E],
       but  in  the German language it is of specialized use; ß does not normally uppercase-transform to it, but
       rather to “SS”.  “Lowercase f with hook” is also used as a function symbol; see subsection  “Mathematical
       symbols” below.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       Ð        \[-D]   u00D0     uppercase eth
       ð        \[Sd]   u00F0     lowercase eth
       Þ        \[TP]   u00DE     uppercase thorn
       þ        \[Tp]   u00FE     lowercase thorn
       ß        \[ss]   u00DF     lowercase sharp s
       ı        \[.i]   u0131     i without tittle
       ȷ        \[.j]   u0237     j without tittle
       ƒ        \[Fn]   u0192     lowercase f with hook, function
       Ł        \[/L]   u0141     L with stroke
       ł        \[/l]   u0142     l with stroke
       Ø        \[/O]   u00D8     O with stroke
       ø        \[/o]   u00F8     o with stroke

   Ligatures and digraphs
       Output   Input   Unicode           Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ff       \[ff]   u0066_0066        ff ligature +
       fi       \[fi]   u0066_0069        fi ligature +
       fl       \[fl]   u0066_006C        fl ligature +
       ffi      \[Fi]   u0066_0066_0069   ffi ligature +
       ffl      \[Fl]   u0066_0066_006C   ffl ligature +
       Æ        \[AE]   u00C6             AE ligature
       æ        \[ae]   u00E6             ae ligature
       Œ        \[OE]   u0152             OE ligature
       œ        \[oe]   u0153             oe ligature
       IJ        \[IJ]   u0132             IJ digraph

       ij        \[ij]   u0133             ij digraph

   Accents
       Normally,  the  formatting  of a special character advances the drawing position as an ordinary character
       does.  groff's composite request designates a special character as combining.  The  composite.tmac  macro
       file, loaded automatically by the default troffrc, maps the following special characters to the combining
       characters shown below.  The non-combining code point in parentheses is used when the  special  character
       occurs in isolation (compare “caf\[e aa]” and “caf\[aa]e”).

       Output   Input   Unicode         Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ˝        \[a"]   u030B (u02DD)   double acute accent
       ¯        \[a-]   u0304 (u00AF)   macron accent
       ˙        \[a.]   u0307 (u02D9)   dot accent
       ^        \[a^]   u0302 (u005E)   circumflex accent
       ´        \[aa]   u0301 (u00B4)   acute accent +
       `        \[ga]   u0300 (u0060)   grave accent +
       ˘        \[ab]   u0306 (u02D8)   breve accent
       ¸        \[ac]   u0327 (u00B8)   cedilla accent
       ¨        \[ad]   u0308 (u00A8)   dieresis accent
       ˇ        \[ah]   u030C (u02C7)   caron accent
       ˚        \[ao]   u030A (u02DA)   ring accent
       ~        \[a~]   u0303 (u007E)   tilde accent
       ˛        \[ho]   u0328 (u02DB)   hook accent

   Accented characters
       All  of  these  glyphs  can  be  composed using combining glyph names as described in subsection “Special
       character escape forms” above; the names below are short aliases for convenience.

       Output   Input   Unicode      Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       Á        \['A]   u0041_0301   A acute
       Ć        \['C]   u0043_0301   C acute
       É        \['E]   u0045_0301   E acute
       Í        \['I]   u0049_0301   I acute
       Ó        \['O]   u004F_0301   O acute
       Ú        \['U]   u0055_0301   U acute
       Ý        \['Y]   u0059_0301   Y acute
       á        \['a]   u0061_0301   a acute
       ć        \['c]   u0063_0301   c acute
       é        \['e]   u0065_0301   e acute
       í        \['i]   u0069_0301   i acute
       ó        \['o]   u006F_0301   o acute
       ú        \['u]   u0075_0301   u acute
       ý        \['y]   u0079_0301   y acute

       Ä        \[:A]   u0041_0308   A dieresis
       Ë        \[:E]   u0045_0308   E dieresis
       Ï        \[:I]   u0049_0308   I dieresis
       Ö        \[:O]   u004F_0308   O dieresis
       Ü        \[:U]   u0055_0308   U dieresis
       Ÿ        \[:Y]   u0059_0308   Y dieresis
       ä        \[:a]   u0061_0308   a dieresis
       ë        \[:e]   u0065_0308   e dieresis
       ï        \[:i]   u0069_0308   i dieresis
       ö        \[:o]   u006F_0308   o dieresis
       ü        \[:u]   u0075_0308   u dieresis
       ÿ        \[:y]   u0079_0308   y dieresis

       Â        \[^A]   u0041_0302   A circumflex
       Ê        \[^E]   u0045_0302   E circumflex
       Î        \[^I]   u0049_0302   I circumflex
       Ô        \[^O]   u004F_0302   O circumflex
       Û        \[^U]   u0055_0302   U circumflex
       â        \[^a]   u0061_0302   a circumflex
       ê        \[^e]   u0065_0302   e circumflex
       î        \[^i]   u0069_0302   i circumflex
       ô        \[^o]   u006F_0302   o circumflex
       û        \[^u]   u0075_0302   u circumflex

       À        \[`A]   u0041_0300   A grave
       È        \[`E]   u0045_0300   E grave

       Ì        \[`I]   u0049_0300   I grave
       Ò        \[`O]   u004F_0300   O grave
       Ù        \[`U]   u0055_0300   U grave
       à        \[`a]   u0061_0300   a grave
       è        \[`e]   u0065_0300   e grave
       ì        \[`i]   u0069_0300   i grave
       ò        \[`o]   u006F_0300   o grave
       ù        \[`u]   u0075_0300   u grave

       Ã        \[~A]   u0041_0303   A tilde
       Ñ        \[~N]   u004E_0303   N tilde
       Õ        \[~O]   u004F_0303   O tilde
       ã        \[~a]   u0061_0303   a tilde
       ñ        \[~n]   u006E_0303   n tilde
       õ        \[~o]   u006F_0303   o tilde

       Š        \[vS]   u0053_030C   S caron
       š        \[vs]   u0073_030C   s caron
       Ž        \[vZ]   u005A_030C   Z caron
       ž        \[vz]   u007A_030C   z caron

       Ç        \[,C]   u0043_0327   C cedilla
       ç        \[,c]   u0063_0327   c cedilla

       Å        \[oA]   u0041_030A   A ring
       å        \[oa]   u0061_030A   a ring

   Quotation marks
       The neutral double quote, often useful when documenting programming languages, is  also  available  as  a
       special character for convenient embedding in macro arguments; see subsection “Fundamental character set”
       above.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       „        \[Bq]   u201E     low double comma quote
       ‚        \[bq]   u201A     low single comma quote
       “        \[lq]   u201C     left double quote
       ”        \[rq]   u201D     right double quote
       ‘        \[oq]   u2018     single opening (left) quote
       ’        \[cq]   u2019     single closing (right) quote
       '        \[aq]   u0027     apostrophe, neutral single quote
       "        "       u0022     neutral double quote
       "        \[dq]   u0022     neutral double quote
       «        \[Fo]   u00AB     left double chevron
       »        \[Fc]   u00BB     right double chevron
       ‹        \[fo]   u2039     left single chevron
       ›        \[fc]   u203A     right single chevron

   Punctuation
       The Unicode name for U+00B7 is “middle dot”, which is unfortunately confusable with  the  groff  mnemonic
       for  the  visually  similar  but  semantically  distinct multiplication dot; see subsection “Mathematical
       symbols” below.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ¡        \[r!]   u00A1     inverted exclamation mark
       ¿        \[r?]   u00BF     inverted question mark
       ·        \[pc]   u00B7     centered period
       —        \[em]   u2014     em-dash +
       –        \[en]   u2013     en-dash
       ‐        \[hy]   u2010     hyphen +

   Brackets
       On typesetting devices, the bracket extensions are font-invariant glyphs; that is, they are rendered  the
       same way regardless of font (with a drawing escape sequence).  On terminals, they are not font-invariant;
       groff maps them rather arbitrarily to U+23AA (“curly bracket extension”).  In AT&T troff, only one  glyph
       was available to vertically extend brackets, braces, and parentheses: \(bv.

       Not  all  devices  supply  bracket  pieces  that  can  be piled up with \b due to the restrictions of the
       escape's piling algorithm.  A general solution to build brackets out of pieces is the following macro:
              .\" Make a pile centered vertically 0.5em above the baseline.
              .\" The first argument is placed at the top.
              .\" The pile is returned in string 'pile'.
              .eo
              .de pile-make
              .  nr pile-wd 0
              .  nr pile-ht 0
              .  ds pile-args
              .
              .  nr pile-# \n[.$]
              .  while \n[pile-#] \{\
              .    nr pile-wd (\n[pile-wd] >? \w'\$[\n[pile-#]]')
              .    nr pile-ht +(\n[rst] - \n[rsb])
              .    as pile-args \v'\n[rsb]u'\"
              .    as pile-args \Z'\$[\n[pile-#]]'\"
              .    as pile-args \v'-\n[rst]u'\"
              .    nr pile-# -1
              .  \}
              .
              .  ds pile \v'(-0.5m + (\n[pile-ht]u / 2u))'\"
              .  as pile \*[pile-args]\"
              .  as pile \v'((\n[pile-ht]u / 2u) + 0.5m)'\"
              .  as pile \h'\n[pile-wd]u'\"
              ..
              .ec

       Another complication is the fact that some glyphs which represent bracket pieces in  AT&T  troff  can  be
       used for other mathematical symbols as well, for example \(lf and \(rf, which provide the floor operator.
       Some output devices, such as dvi, don't unify such glyphs.  For this reason,  the  glyphs  \[lf],  \[rf],
       \[lc],  and  \[rc]  are not unified with similar-looking bracket pieces.  In groff, only glyphs with long
       names are guaranteed to pile up correctly for all devices—provided those glyphs are available.

       Output   Input               Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       [        [                   u005B     left square bracket
       [        \[lB]               u005B     left square bracket
       ]        ]                   u005D     right square bracket
       ]        \[rB]               u005D     right square bracket
       {        {                   u007B     left brace
       {        \[lC]               u007B     left brace
       }        }                   u007D     right brace
       }        \[rC]               u007D     right brace
       ⟨        \[la]               u27E8     left angle bracket
       ⟩        \[ra]               u27E9     right angle bracket
       ⎪        \[bv]               u23AA     brace vertical extension + ***
       ⎪        \[braceex]          u23AA     brace vertical extension

       ⎡        \[bracketlefttp]    u23A1     left square bracket top
       ⎢        \[bracketleftex]    u23A2     left square bracket extension
       ⎣        \[bracketleftbt]    u23A3     left square bracket bottom

       ⎤        \[bracketrighttp]   u23A4     right square bracket top
       ⎥        \[bracketrightex]   u23A5     right square bracket extension
       ⎦        \[bracketrightbt]   u23A6     right square bracket bottom

       ⎧        \[lt]               u23A7     left brace top +
       ⎨        \[lk]               u23A8     left brace middle +
       ⎩        \[lb]               u23A9     left brace bottom +
       ⎧        \[bracelefttp]      u23A7     left brace top
       ⎨        \[braceleftmid]     u23A8     left brace middle
       ⎩        \[braceleftbt]      u23A9     left brace bottom
       ⎪        \[braceleftex]      u23AA     left brace extension

       ⎫        \[rt]               u23AB     right brace top +
       ⎬        \[rk]               u23AC     right brace middle +
       ⎭        \[rb]               u23AD     right brace bottom +
       ⎫        \[bracerighttp]     u23AB     right brace top
       ⎬        \[bracerightmid]    u23AC     right brace middle
       ⎭        \[bracerightbt]     u23AD     right brace bottom
       ⎪        \[bracerightex]     u23AA     right brace extension

       ⎛        \[parenlefttp]      u239B     left parenthesis top
       ⎜        \[parenleftex]      u239C     left parenthesis extension
       ⎝        \[parenleftbt]      u239D     left parenthesis bottom
       ⎞        \[parenrighttp]     u239E     right parenthesis top

       ⎟        \[parenrightex]     u239F     right parenthesis extension
       ⎠        \[parenrightbt]     u23A0     right parenthesis bottom

   Arrows
       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ←        \[<-]   u2190     horizontal arrow left +
       →        \[->]   u2192     horizontal arrow right +
       ↔        \[<>]   u2194     bidirectional horizontal arrow
       ↓        \[da]   u2193     vertical arrow down +
       ↑        \[ua]   u2191     vertical arrow up +
       ↕        \[va]   u2195     bidirectional vertical arrow
       ⇐        \[lA]   u21D0     horizontal double arrow left
       ⇒        \[rA]   u21D2     horizontal double arrow right
       ⇔        \[hA]   u21D4     bidirectional horizontal double arrow
       ⇓        \[dA]   u21D3     vertical double arrow down
       ⇑        \[uA]   u21D1     vertical double arrow up
       ⇕        \[vA]   u21D5     bidirectional vertical double arrow
       ⎯        \[an]   u23AF     horizontal arrow extension

   Rules and lines
       On typesetting devices, the font-invariant glyphs (see subsection “Brackets”  above)  \[br],  \[ul],  and
       \[rn]  form corners when adjacent; they can be used to build boxes.  On terminal devices, they are mapped
       as shown in the table.  The Unicode-derived names of these three glyphs are approximations.

       The input character _ always accesses the underscore glyph in a font; \[ul], by contrast,  may  be  font-
       invariant on typesetting devices.

       The baseline rule \[ru] is a font-invariant glyph, namely a rule of one-half em.

       In  AT&T  troff,  \[rn]  also  served  as  a  one  en  extension of the square root symbol.  groff favors
       \[radicalex] for this purpose; see subsection “Mathematical symbols” below.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       |        |       u007C     bar
       |        \[ba]   u007C     bar
       │        \[br]   u2502     box rule +
       _        _       u005F     underscore, low line +
       _        \[ul]   ---       underrule +
       ‾        \[rn]   u203E     overline +
       _        \[ru]   ---       baseline rule +
       ¦        \[bb]   u00A6     broken bar
       /        /       u002F     slash, solidus +
       /        \[sl]   u002F     slash, solidus +
       \        \[rs]   u005C     reverse solidus

   Text markers
       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ○        \[ci]   u25CB     circle +
       •        \[bu]   u2022     bullet +
       †        \[dg]   u2020     dagger +
       ‡        \[dd]   u2021     double dagger +
       ◊        \[lz]   u25CA     lozenge, diamond
       □        \[sq]   u25A1     square +
       ¶        \[ps]   u00B6     pilcrow sign
       §        \[sc]   u00A7     section sign +
       ☜        \[lh]   u261C     hand pointing left +
       ☞        \[rh]   u261E     hand pointing right +
       @        @       u0040     at sign
       @        \[at]   u0040     at sign
       #        #       u0023     number sign
       #        \[sh]   u0023     number sign
       ↵        \[CR]   u21B5     carriage return
       ✓        \[OK]   u2713     check mark

   Legal symbols
       The Bell System logo is not supported in groff.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ©        \[co]   u00A9     copyright sign +

       ®        \[rg]   u00AE     registered sign +
       ™        \[tm]   u2122     trade mark sign
                \[bs]   ---       Bell System logo +

   Currency symbols
       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       $        $       u0024     dollar sign
       $        \[Do]   u0024     dollar sign
       ¢        \[ct]   u00A2     cent sign +
       €        \[eu]   u20AC     Euro sign
       €        \[Eu]   u20AC     variant Euro sign
       ¥        \[Ye]   u00A5     yen sign
       £        \[Po]   u00A3     pound sign
       ¤        \[Cs]   u00A4     currency sign

   Units
       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       °        \[de]   u00B0     degree sign +
       ‰        \[%0]   u2030     per thousand, per mille sign
       ′        \[fm]   u2032     arc minute sign, foot mark +
       ″        \[sd]   u2033     arc second sign
       µ        \[mc]   u00B5     micro sign
       ª        \[Of]   u00AA     feminine ordinal indicator
       º        \[Om]   u00BA     masculine ordinal indicator

   Logical symbols
       The variants of the not sign may differ in appearance  or  spacing  depending  on  the  device  and  font
       selected.   Unicode  does  not  encode  a discrete “bitwise or” sign: on typesetting devices, it is drawn
       shorter than the bar, about the same height as a capital letter.  Terminal devices unify \[ba] and \[or].

       Output   Input    Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ∧        \[AN]    u2227     logical and
       ∨        \[OR]    u2228     logical or
       ¬        \[no]    u00AC     logical not + ***
       ¬        \[tno]   u00AC     text variant of \[no]
       ∃        \[te]    u2203     there exists
       ∀        \[fa]    u2200     for all
       ∋        \[st]    u220B     such that
       ∴        \[3d]    u2234     therefore
       ∴        \[tf]    u2234     therefore
       |        |        u007C     bar
       |        \[or]    u007C     bitwise or +

   Mathematical symbols
       \[Fn] also appears in subsection “Supplementary Latin letters” above.  Observe the two varieties  of  the
       plus-minus,  multiplication,  and  division  signs;  \[+-],  \[mu], and \[di] are normally drawn from the
       special font, but have text font variants.  Also be aware of  three  glyphs  available  in  special  font
       variants  that are normally drawn from text fonts: the plus, minus, and equals signs.  These variants may
       differ in appearance or spacing depending on the device and font selected.

       In AT&T troff, \(rn (“root en extender”) served as the horizontal extension of the radical (square  root)
       sign,  \(sr, and was drawn at the maximum height of the typeface's bounding box; this enabled the special
       character to double as an overline (see subsection “Rules  and  lines”  above).   A  contemporary  font's
       radical sign might not ascend to such an extreme.  In groff, you can instead use \[radicalex] to continue
       the radical sign \[sr]; these special characters are intended for  use  with  text  fonts.   \[sqrt]  and
       \[sqrtex] are their counterparts with mathematical spacing.

       Output   Input          Unicode      Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ½        \[12]          u00BD        one half symbol +
       ¼        \[14]          u00BC        one quarter symbol +
       ¾        \[34]          u00BE        three quarters symbol +
       ⅛        \[18]          u215B        one eighth symbol
       ⅜        \[38]          u215C        three eighths symbol
       ⅝        \[58]          u215D        five eighths symbol
       ⅞        \[78]          u215E        seven eighths symbol
       ¹        \[S1]          u00B9        superscript one
       ²        \[S2]          u00B2        superscript two
       ³        \[S3]          u00B3        superscript three

       +        +              u002B        plus
       +        \[pl]          u002B        special variant of plus + ***
       -        \[-]           u002D        minus
       −        \[mi]          u2212        special variant of minus + ***
       ∓        \[-+]          u2213        minus-plus
       ±        \[+-]          u00B1        plus-minus + ***
       ±        \[t+-]         u00B1        text variant of \[+-]
       ⋅        \[md]          u22C5        multiplication dot
       ×        \[mu]          u00D7        multiplication sign + ***
       ×        \[tmu]         u00D7        text variant of \[mu]
       ⊗        \[c*]          u2297        circled times
       ⊕        \[c+]          u2295        circled plus
       ÷        \[di]          u00F7        division sign + ***
       ÷        \[tdi]         u00F7        text variant of \[di]
       ⁄        \[f/]          u2044        fraction slash
       *        *              u002A        asterisk
       ∗        \[**]          u2217        mathematical asterisk +

       ≤        \[<=]          u2264        less than or equal to +
       ≥        \[>=]          u2265        greater than or equal to +
       ≪        \[<<]          u226A        much less than
       ≫        \[>>]          u226B        much greater than
       =        =              u003D        equals
       =        \[eq]          u003D        special variant of equals + ***
       ≠        \[!=]          u003D_0338   not equals +
       ≡        \[==]          u2261        equivalent +
       ≢        \[ne]          u2261_0338   not equivalent
       ≅        \[=~]          u2245        approximately equal to
       ≃        \[|=]          u2243        asymptotically equal to +
       ~        \[ti]          u007E        tilde +
       ∼        \[ap]          u223C        similar to, tilde operator +
       ≈        \[~~]          u2248        almost equal to
       ≈        \[~=]          u2248        almost equal to
       ∝        \[pt]          u221D        proportional to +

       ∅        \[es]          u2205        empty set +
       ∈        \[mo]          u2208        element of a set +
       ∉        \[nm]          u2208_0338   not element of set
       ⊂        \[sb]          u2282        proper subset +
       ⊄        \[nb]          u2282_0338   not subset
       ⊃        \[sp]          u2283        proper superset +
       ⊅        \[nc]          u2283_0338   not superset
       ⊆        \[ib]          u2286        subset or equal +
       ⊇        \[ip]          u2287        superset or equal +
       ∩        \[ca]          u2229        intersection, cap +
       ∪        \[cu]          u222A        union, cup +

       ∠        \[/_]          u2220        angle
       ⊥        \[pp]          u22A5        perpendicular
       ∫        \[is]          u222B        integral +
       ∫        \[integral]    u222B        integral ***
       ∑        \[sum]         u2211        summation ***
       ∏        \[product]     u220F        product ***
       ∐        \[coproduct]   u2210        coproduct ***
       ∇        \[gr]          u2207        gradient +
       √        \[sr]          u221A        radical sign, square root +
       ‾        \[rn]          u203E        overline +
                \[radicalex]   ---          radical extension
       √        \[sqrt]        u221A        radical sign, square root ***
                \[sqrtex]      ---          radical extension ***

       ⌈        \[lc]          u2308        left ceiling +
       ⌉        \[rc]          u2309        right ceiling +
       ⌊        \[lf]          u230A        left floor +
       ⌋        \[rf]          u230B        right floor +

       ∞        \[if]          u221E        infinity +
       ℵ        \[Ah]          u2135        aleph symbol
       ƒ        \[Fn]          u0192        lowercase f with hook, function
       ℑ        \[Im]          u2111        blackletter I, imaginary part
       ℜ        \[Re]          u211C        blackletter R, real part
       ℘        \[wp]          u2118        Weierstrass p
       ∂        \[pd]          u2202        partial differential

       ℏ        \[-h]          u210F        h bar
       ℏ        \[hbar]        u210F        h bar

   Greek glyphs
       These  glyphs  are  intended  for  technical  use, not for typesetting Greek language text; normally, the
       uppercase letters have upright shape, and the lowercase ones are slanted.

       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       Α        \[*A]   u0391     uppercase alpha +
       Β        \[*B]   u0392     uppercase beta +
       Γ        \[*G]   u0393     uppercase gamma +
       Δ        \[*D]   u0394     uppercase delta +
       Ε        \[*E]   u0395     uppercase epsilon +
       Ζ        \[*Z]   u0396     uppercase zeta +
       Η        \[*Y]   u0397     uppercase eta +
       Θ        \[*H]   u0398     uppercase theta +
       Ι        \[*I]   u0399     uppercase iota +
       Κ        \[*K]   u039A     uppercase kappa +
       Λ        \[*L]   u039B     uppercase lambda +
       Μ        \[*M]   u039C     uppercase mu +
       Ν        \[*N]   u039D     uppercase nu +
       Ξ        \[*C]   u039E     uppercase xi +
       Ο        \[*O]   u039F     uppercase omicron +
       Π        \[*P]   u03A0     uppercase pi +
       Ρ        \[*R]   u03A1     uppercase rho +
       Σ        \[*S]   u03A3     uppercase sigma +
       Τ        \[*T]   u03A4     uppercase tau +
       Υ        \[*U]   u03A5     uppercase upsilon +
       Φ        \[*F]   u03A6     uppercase phi +
       Χ        \[*X]   u03A7     uppercase chi +
       Ψ        \[*Q]   u03A8     uppercase psi +
       Ω        \[*W]   u03A9     uppercase omega +

       α        \[*a]   u03B1     lowercase alpha +
       β        \[*b]   u03B2     lowercase beta +
       γ        \[*g]   u03B3     lowercase gamma +
       δ        \[*d]   u03B4     lowercase delta +
       ε        \[*e]   u03B5     lowercase epsilon +
       ζ        \[*z]   u03B6     lowercase zeta +
       η        \[*y]   u03B7     lowercase eta +
       θ        \[*h]   u03B8     lowercase theta +
       ι        \[*i]   u03B9     lowercase iota +
       κ        \[*k]   u03BA     lowercase kappa +
       λ        \[*l]   u03BB     lowercase lambda +
       μ        \[*m]   u03BC     lowercase mu +
       ν        \[*n]   u03BD     lowercase nu +
       ξ        \[*c]   u03BE     lowercase xi +
       ο        \[*o]   u03BF     lowercase omicron +
       π        \[*p]   u03C0     lowercase pi +
       ρ        \[*r]   u03C1     lowercase rho +
       σ        \[*s]   u03C3     lowercase sigma +
       τ        \[*t]   u03C4     lowercase tau +
       υ        \[*u]   u03C5     lowercase upsilon +
       ϕ        \[*f]   u03D5     lowercase phi +
       χ        \[*x]   u03C7     lowercase chi +
       ψ        \[*q]   u03C8     lowercase psi +
       ω        \[*w]   u03C9     lowercase omega +

       ϵ        \[+e]   u03F5     variant epsilon (lunate)
       ϑ        \[+h]   u03D1     variant theta (cursive form)
       ϖ        \[+p]   u03D6     variant pi (similar to omega)
       φ        \[+f]   u03C6     variant phi (curly shape)
       ς        \[ts]   u03C2     terminal lowercase sigma +

   Playing card symbols
       Output   Input   Unicode   Notes
       ──────────────────────────────────────────────────────────────────────────────────────────────────────────
       ♣        \[CL]   u2663     solid club suit
       ♠        \[SP]   u2660     solid spade suit
       ♥        \[HE]   u2665     solid heart suit
       ♦        \[DI]   u2666     solid diamond suit

History

       A consideration of  the  typefaces  originally  available  to  AT&T  nroff  and  troff  illuminates  many
       conventions  that  one  might  regard  as idiosyncratic fifty years afterward.  (See section “History” of
       roff(7) for more context.)  The face used by the Teletype Model 37 terminals of the Murray Hill Unix Room
       was based on ASCII, but assigned multiple meanings to several code points, as suggested by that standard.
       Decimal 34 (") served as a dieresis accent and neutral double quotation mark; decimal 39 (') as an  acute
       accent,  apostrophe,  and  closing  (right) single quotation mark; decimal 45 (-) as a hyphen and a minus
       sign; decimal 94 (^) as a circumflex accent and caret; decimal 96 (`)  as  a  grave  accent  and  opening
       (left)  single  quotation mark; and decimal 126 (~) as a tilde accent and (with a half-line motion) swung
       dash.  The Model 37 bore an optional extended character set offering upright Greek  letters  and  several
       mathematical symbols; these were documented as early as the kbd(VII) man page of the (First Edition) Unix
       Programmer's Manual.

       At the time Graphic Systems delivered the C/A/T phototypesetter to AT&T, the ASCII character set was  not
       considered  a  standard  basis  for  a  glyph repertoire by traditional typographers.  In the stock Times
       roman, italic, and bold styles available, several ASCII characters were not present at all, nor was  most
       of  the  Teletype's  extended  character  set.   AT&T  commissioned a “special” font to ensure no loss of
       repertoire.

       A representation of the coverage of the C/A/T's text fonts follows.  The glyph resembling  an  underscore
       is  a baseline rule, and that resembling a vertical line is a box rule.  In italics, the box rule was not
       slanted.  We also observe that the hyphen and minus sign were already “de-unified” by the fonts provided;
       a decision whither to map an input “-” therefore had to be taken.

                                 ┌────────────────────────────────────────────────────┐
                                 │A B C D E F G H I J K L M N O P Q R S T U V W X Y Z │
                                 │a b c d e f g h i j k l m n o p q r s t u v w x y z │
                                 │0 1 2 3 4 5 6 7 8 9 fi fl ffi ffl                   │
                                 │! $ % & ( ) ‘ ’ * + - . , / : ; = ? [ ] │           │
                                 │• □ — ‐ _ ¼ ½ ¾ ° † ′ ¢ ® ©                         │
                                 └────────────────────────────────────────────────────┘
       The  special  font  supplied  the  missing ASCII and Teletype extended glyphs, among several others.  The
       plus, minus, and equals signs appeared in the  special  font  despite  availability  in  text  fonts  “to
       insulate  the  appearance  of  equations from the choice of standard [read: text] fonts”—a priority since
       troff was turned to the task of mathematical typesetting as soon as it was developed.

       We note that AT&T took the opportunity to de-unify the apostrophe/right single quotation  mark  from  the
       acute  accent  (a  choice  ISO later duplicated in its 8859 series of standards).  A slash intended to be
       mirror-symmetric with the backslash was also included, as was the Bell System logo; we do not attempt  to
       depict the latter.

                              ┌─────────────────────────────────────────────────────────┐
                              │α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ ς τ υ ϕ χ ψ ω        │
                              │Γ Δ Θ Λ Ξ Π Σ Υ Φ Ψ Ω                                    │
                              │" ´ \ ^ _ ` ~ / < > { } # @ + − = ∗                      │
                              │≥ ≤ ≡ ≈ ∼ ≠ ↑ ↓ ← → × ÷ ± ∞ ∂ ∇ ¬ ∫ ∝ √  ∪ ∩ ⊂ ⊃ ⊆ ⊇ ∅ ∈ │
                              │§ ‡ ☜ ☞ | ○ ⎧ ⎩ ⎫ ⎭ ⎨ ⎬ ⎪ ⌊ ⌋ ⌈ ⌉                        │
                              └─────────────────────────────────────────────────────────┘
       One  ASCII  character  as rendered by the Model 37 was apparently abandoned.  That device printed decimal
       124 (|) as a broken vertical line, like Unicode U+00A6 (¦).  No equivalent was available  on  the  C/A/T;
       the  box  rule  \[br],  brace vertical extension \[bv], and “or” operator \[or] were used as contextually
       appropriate.

       Devices supported by AT&T device-independent troff exhibited  some  differences  in  glyph  detail.   For
       example, on the Autologic APS-5 phototypesetter, the square \(sq became filled in the Times bold face.

Files

       The files below are loaded automatically by the default troffrc.

       /usr/share/groff/1.23.0/tmac/composite.tmac
              assigns alternate mappings for identifiers after the first in a composite special character escape
              sequence.  See subsection “Accents” above.

       /usr/share/groff/1.23.0/tmac/fallbacks.tmac
              defines fallback mappings for Unicode code points such as the increment sign (U+2206)  and  upper-
              and lowercase Roman numerals.

Authors

       This  document was written by James Clark ⟨jjc@jclark.com⟩, with additions by Werner Lemberg ⟨wl@gnu.org⟩
       and Bernd Warken ⟨groff-bernd.warken-72@web.de⟩, revised to use tbl(1) by Eric  S.  Raymond  ⟨esr@thyrsus
       .com⟩, and largely rewritten by G. Branden Robinson ⟨g.branden.robinson@gmail.com⟩.

See also

       Groff:  The  GNU  Implementation  of  troff,  by Trent A. Fisher and Werner Lemberg, is the primary groff
       manual.  Section “Using Symbols” may be of particular note.  You can browse it interactively  with  “info
       '(groff) Using Symbols'”.

       “An  extension  to  the  troff  character set for Europe”, E.G. Keizer, K.J. Simonsen, J. Akkerhuis; EUUG
       Newsletter, Volume 9, No. 2, Summer 1989

       The Unicode Standard ⟨http://www.unicode.org⟩

       “7-bit Character Sets” ⟨https://www.aivosto.com/articles/charsets-7bit.html⟩ by Tuomas  Salste  documents
       the inherent ambiguity and configurable code points of the ASCII encoding standard.

       “Nroff/Troff  User's  Manual”  by  Joseph  F.  Ossanna,  1976,  AT&T  Bell Laboratories Computing Science
       Technical Report No. 54, features two tables that throw  light  on  the  glyph  repertoire  available  to
       “typesetter roff” when it was first written.  Be careful of re-typeset versions of this document that can
       be found on the Internet.  Some do not accurately represent the original  document:  several  glyphs  are
       obviously  missing.   More  subtly,  lowercase  Greek  letters  are rendered upright, not slanted as they
       appeared in the C/A/T's special font and as expected by troff users.

       groff_rfc1345(7) describes an alternative set of special character glyph names, which extends and in some
       cases overrides the definitions listed above.

       groff(1), troff(1), groff(7)