I don't know about earlier version, but Word XP has support for multiple custom spelling dictionaries, which you can turn on or off.
This means that I can add "Birge" to my spelling dictionary for Peks and Word will never ask me to ignore or change it. However, I can deselect that dictionary and it won't think that "Birge" is an acceptable mis-spelling of "bridge" or anything.
However, it's not the most convenient to use. I believe if you have multiple dictionaries in use (like the default one, that has real words added to it that the inadequate base dictionary did NOT contain, like "Ehlers," or such) and you "add" the word to the dictionary, it adds to ALL dictionaries in use. This means you have to go through your document once with just the novel-specific custom dictionary to add them to and avoid getting them in your default custom dictionary.
Kind of a pain, but if like me you open and close that document and hate having it underline your protagonist's name every single time, you can do it once and it will remember. Works better than "ignore" but allows you to still use the spelling feature.
Just thought I'd share.
