An author may want to use particular spellings of words, as dialect, for instance, and may want to avoid having spell check find every instance of words it deems "wrong", when those were the intentions of the writer to have those words spelled in a particular way.
Elina Hellsten commented
Can the spell-checker be turned off? I don't write in English and it probably wants to correct every single word.
AdminBenji Smith (Founder, Shaxpir) commented
This is a very important feature to me, and it's one of the reasons the 1.0 beta version doesn't ship with a spell-check function. Spell-checking in fiction is different than spell-checking in business documents, and I want to build a spell-checker that's specifically tailored to the needs of fiction authors.