It's not strictly limited to proper nouns -- try "jury nullification" or "obfuscated code" for example. However, if the matching title is a proper noun, it req

It's not strictly limited to proper nouns -- try "jury nullification" or "obfuscated code" for example. However, if the matching title is a proper noun, it requires exact case match. This is a side-effect of relying heavily on case for matching in order to prevent accidental or overzealous matches. This is in fact a fairly thorny problem, at least without some sort of semantic parser.