Is there a word for that quality which a word or phrase may have that marks it to our ears as a proper noun? Depending on your frame of reference certain words are obviously names, such as David or James, and other names are understood to have non-proper homophones, such as Bob or Sally. Other names, depending on your cultural background, at first seem not to be names, such as many Native American names, but one acquires a familiary with them so that, for example, Sitting Bull or Dances With Wolves immediately sound like a proper names rather than descriptions of a reclining male of the subfamily Bovinae or a lupine cotillion.

So, is there a name for the characteristic itself, that ring of nomenclature?