One of the more confusing versions of this I came in contact with recently is the 23 pin amiga rgb port. It has no real official D-subminature name as there is no such designation for the shell of a 12+11 pin port, which I assume is due to the fact that it was for a non-IBM machine...BUT some sellers (on aliexpress) DO call it a DB-23 port...I did figure it out eventually and got a few but it did take a while after searching for "12+11 serial" and being a bit frustrated at not finding anything.