Currently, a lot of personal names come up in the Thunderbird spell checker as possible mis-spelt words. I can add them as words to my personal dictionary, but what I'd like to have is the option to add a queried word as a personal name. Then, if the spell checker queried it in future, it would recognise it as a name, and offer me variant spellings of the same name, rather than unrelated words. For example, I might write emails to people with the surname Eliot, Elliot, or Elliott. All correct spellings. I'd like the spell checker to offer me the other variations when I write one of them, so I can check I haven't missed a 't' from Elliott by mistake. There's lots of other examples; I might write to someone with the family name Hussein or Hussain, Smith or Smyth, or Smythe.