It's a very different thing from raincoat vs. rain coat. Those sort of combinations happen all the time, and either can be considered correct. This is a whole

It's a very different thing from raincoat vs. rain coat. Those sort of combinations happen all the time, and either can be considered correct. This is a whole class of words that are always two words when used as a verb, and one word when used as a noun. Setup/set up, login/log in, lookup/look up, checkout/check out, etc. I guess you can claim it is petty, but to me it is like using the wrong "there". Especially bad in a title.