1. International Ispell (an interactive spelling corrector) Ispell corrects spelling in plain text, LaTeX, sgml/html/xml, and nroff files. [x]Emacs and jed have nice interfaces to ispell, and ispell works from many other tools and from the command line as well. No dictionaries are included in this package. Ispell looks in /usr/lib/ispell/default.{aff,hash} and in /usr/share/dict/words by default. Those files may be provided, respectively, by an ispell-dictionary package and a wordlist package. (You must have an ispell dictionary before you can use ispell; a wordlist is only required for ispell's (L)ookup command.) This ispell package supports either the "new-style" idict-<language> dictionaries or the "old-style" i<language> dictionaries. As of February 2001, only old-style dictionaries are available, because the dictionaries-common standards and package have not been finalized. When dictionaries-common and the idict-<language> dictionaries become available, this version of ispell will be able to use them. (For more information, please see the dictionaries-common package and ispell's Debian changelog). From Debian 3.0r0 APT

2. format of ispell dictionaries and affix files From whatis