Michael E. Deisher writes ("Re: Bug#2425: ispell thinks `formated' is correct"):
...
> Webster Definition for "formate"
> for.mate \-.ma-t\ n : a salt or ester of formic acid
OK, so it's a word (in American, and chemistry being what it is in
English too) - but it's still a noun, so you can't have `formated'.
Ian.