I looked into adding a spell-checker about a year ago, but none of them are very appealing. The good ones cost money.
I am deep into updating (that is: procuring the updates and reading the READMEs; not writing the code) the MOD files right now, but if you want to run a search on "phpBB spellchecker" and do some looking at the various alternatives, I'm listening. Best to take it to the Support forum though.
83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles 82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!