Words that were created in dictionaries, glossaries, or lexicons, including
1) Words for which no evidence for their occurrence in print outside of dictionaries and glossaries has yet been found, but where the entries appear to be bona fide attempts to record their existence in a particular language (e.g.,
alabandical,
pierelle).
2) Words inserted in dictionaries as jokes or hoaxes (
pneumonoultramicroscopicsilicovolcanoconiosis), or to guard against copyright violations (
esquivalience).
3) Words created to provide technical vocabulary in a particular subject area (
cryptoscopophilia).
4) Words created by some form of editorial lapse (
dord).
5) Variant spellings created by editorial attempts to standardize spelling (
youngmannishness).
6) Words that are otherwise unrecorded forms (plurals, principle parts, back-formations) of documented words (
cubomancies).
Also see the list Mountweazels.