The question and answer below was posted in another forum. Is the answer
correct? Did the 23 channel radios effectively lose type acceptance circa
1987 and are not supposed to be used on CB after that time?

Question:
I've heard about that from time to time but never understood - why are
23-channel CBs illegal to sell?
Answer:
Because they are no longer type accepted. Anything after 1987 that is a 23
Ch rig is no longer type accepted and can no longer be sold, traded, given
away, or of course used on the air.. But try to tell that to all the guys
that collect the old Trams and Brownings!