Q. Should “that” be capitalized in titles? Does it depend on usage? Take, for example, this title: “Features of the Website That Are Offered as Premium.” Thanks!
A. The word that is always capitalized in a title. That’s because that’s never a preposition, and though it can function as a conjunction—for example, when it introduces a subordinate clause (e.g., “Tell Me That You Mean It”)—it isn’t one of the five common coordinating conjunctions listed at CMOS 8.160, rule 4 (and, but, for, or, and nor). In your example, “That” is a relative pronoun.