In Yahoo email, is there a way to save word spellings that I use regularly into my own personal dictionary?

I'm looking for a personal dictionalry to save in Yahoo mail. I have several company names and/or people names that are used quite reguarly. It would be nice to be able to save these for future use. Any advise. Thanks for the answer regarding word as I didnt know of that either.
In Yahoo email, is there a way to save word spellings that I use regularly into my own personal dictionary?
The spell checker in yahoo mail is always on. This means it is constantly checking your spelling and showing errors underlined in red. When you right-click on an error (or a proper name), you can save the existing spelling in a dictionary by selecting 'Save to dictionary'. This dictionary is for your use only. Other users cannot add to it.