term% ls -F
term% cat index.txt
SPELL(1)                    General Commands Manual                   SPELL(1)

       spell, spellin, spellout - find spelling errors

       spell [ option ] ...  [ file ] ...

       /usr/src/cmd/spell/spellin [ list ]

       /usr/src/cmd/spell/spellout [ -d ] list

       Spell  collects  words from the named documents, and looks them up in a
       spelling list.  Words that neither occur among nor  are  derivable  (by
       applying  certain  inflections, prefixes or suffixes) from words in the
       spelling list are printed on the standard  output.   If  no  files  are
       named, words are collected from the standard input.

       Spell ignores most troff, tbl and eqn(1) constructions.

       Under  the  -v option, all words not literally in the spelling list are
       printed, and plausible derivations from spelling list words  are  indi‐

       Under  the  -b option, British spelling is checked.  Besides preferring
       centre, colour, speciality, travelled, etc., this option  insists  upon
       -ise in words like standardise, Fowler and the OED to the contrary not‐

       Under the -x option, every plausible stem is printed with `=' for  each

       The  spelling  list  is based on many sources, and while more haphazard
       than an ordinary dictionary, is  also  more  effective  in  respect  to
       proper  names and popular technical words.  Coverage of the specialized
       vocabularies of biology, medicine and chemistry is light.

       Pertinent auxiliary files may be specified by name arguments, indicated
       below  with  their  default settings.  Copies of all output are accumu‐
       lated in the history file.  The  stop  list  filters  out  misspellings
       (e.g. thier=thy-y+ier) that would otherwise pass.

       Two routines help maintain the hash lists used by spell.  Both expect a
       list of words, one per line, from the standard input.  Spellin adds the
       words  on  the  standard input to the preexisting list and places a new
       list on the standard output.  If no list is specified, the new list  is
       created  from scratch.  Spellout looks up each word in the standard in‐
       put and prints on the standard output those that are missing  from  (or
       present on, with option -d) the hash list.

       D=/usr/dict/hlist[ab]: hashed spelling lists, American & British
       S=/usr/dict/hstop: hashed stop list
       H=/usr/dict/spellhist: history file
       deroff(1), sort(1), tee(1), sed(1)

       The spelling list's coverage is uneven; new installations will probably
       wish to monitor the output for several months  to  gather  local  addi‐
       British spelling was done by an American.