- avoid redir msg=avoid a "redirected from" message
- cap or de-cap=changed capitalization of the first letter of a word; if plural, multiple letters and/or words
- clarify=make subject or facts more specific to reduce confusion and/or ambiguity
- crex=corrected facts
- dab=changed link to avoid
either a "redirected from" message, ora disambiguation page - d'oh!=fixed minor mistake I made on previous edit
- fix date=a correction, or better linkage
- fxd=fixed (IE a commonly misspelled word)
- fixed link=turned red link into blue link, usually by making a small word all lowercase, or by moving a plural "s" outside the ]]
- fmt=any sort of formatting, plus adding the subject to the intro (can include adding links if it's a new, raw-text submission
- gram=changed wording, punctuation, etc. to read better, or, more often, just to be more correct English
- imdb=added imdb.com link
- locate=make it more clear where in the world the subject is
- rdndnt=redundant (I've used a few different shorter forms, actually)
- -sig=removed previous contributor's name or date/time/name stamp from an article
- sp=corrected spelling
- stub=added stub msg
- tweak=assorted changes that change presentation, but not basic content
- typo=minor correction of cap, gram, or sp
- wik=combination of fmt and linkage (short for wikify, basically)
From what I remember, I believe any others I use are common and/or obvious