SQ=Show Quality. A highly overused term.
In reality, it means anything that would not suffer a DQ (disqualification) in a show hall. It might be the last place bird out of a thousand, but it's still show quality if it wasn't DQ'd.
Edited to add:
BQ=Breeder Quality. Those birds that are theoretically still beneficial to the breed but have an undesirable trait or traits that keeps them from the show halls. In other words, what most of the SQ labeled birds would hope to be on their best day. Yes, that's a comment dripping with sarcasm.
In reality, it means anything that would not suffer a DQ (disqualification) in a show hall. It might be the last place bird out of a thousand, but it's still show quality if it wasn't DQ'd.

Edited to add:
BQ=Breeder Quality. Those birds that are theoretically still beneficial to the breed but have an undesirable trait or traits that keeps them from the show halls. In other words, what most of the SQ labeled birds would hope to be on their best day. Yes, that's a comment dripping with sarcasm.

Last edited: