<<and I asked him about squawk idents. He started to explain why there are no 8's and 9's used in squawk idents. >>
"Squawk Ident" has nothing to with the number of codes. It is simply a feature of the transponder which, when activated, produces an indication on the radar tube for a few seconds to confirm the identity of the aircraft. Never press the "ident" button unless instructed to do so by ATC.