English Convention of Capitalization in Titles

English has a convention in capitalization of titles. For example, {for, of, a} are usually all lower case. For example: 〈A Tale of Two Cities〉. Note that even the first word is “a”, but it should be capitalized. I thought this is pretty much the only exception. But I discovered a good example today:

The name of the song 〈For What You Dream Of〉. Bedrock -- For What You Dream Of (Trainspotting)

There, the “of” in the end, should be capitalized. I'm not aware of any source that has detail of all the rules of this convention. (preferably, a algorithm) Normally it's like you know when you see it. Do you know a source that describes this title capitalized convention completely?