GA Callsigns

I've found when a controller starts referring to me as "November xxx" it
usually means he either didn't hear my aircraft type on the initial call, or
he forgot it. A couple of times over the last few months when approach has
been calling me "November xxx", they've later asked for my aircraft type
before calling me out as traffic to another plane.

Generally, I hear a terse "NOVEMBER xxxxx" when I'm not paying
attention and they've call me a coupla times.
Sightseeing, BSing with pax, etc.