It's handled at the OS level, rather than by OS X itself. What you can do is just tell the dictionary to learn these words - select a word that normally gets corrected (hit undo after it gets corrected so that it reverts to the original) and which has the red misspelling underline beneath it, ctrl-click it, and select "Learn Spelling". I think that should do the trick.
"You can't waltz in here, use my toaster, and start spouting universal truths without qualification."
Here's a more difficult query. I have a 10,339-word custom dictionary that I built after using Word for many years, and would like to import the whole lot into Scrivener's dictionary, and to add to it over time.
Is that possible? I suppose what I'm looking for is a way to directly edit the custom dictionary, as well as adding to it incrementally. Direct editing is good for weeding out erroneous entries.
This is a operating system level thing, as most applications don't have their own dictionaries/spell checkers. But to get your custom dictionary out of Word, I found the following directions (assumes you are moving the dictionary from Word for Windows, there may be a similar file under ~/Library somewhere). http://answers.yahoo.com/question/index ... 047AA3WpCV
I don't know what format of the file retrieved above will be, as I don't have access to Word at the moment...