usually untitled entities get their title field [put in brackets] (see guidelines on special purpose artists and track titles). one minor issue is sometimes an entity will have a title in brackets as the actual name. some examples of various entities in my library

• Release “[pause]” by lil indigo (and the recording and work associated with the single)
• Release “[夏日]” by マクロスMACROSS 82–99
• Artist “[voodoopony]”
• many tracks on Release “Snö” by Snail’s House (and several more songs by Snail’s House)
• Artist “[sushi]”
• …and many more I've come across, in most all entity types

I think having a way to mark entities as being [untitled] would be beneficial, as I don’t think we can rely on [brackets] to always denote the [untitled]-ness of an entity