they can't be registered as pits u can register it as a staff if u know someone who's just had a litter and say theres one more pup than there is.
if the police see it and think it's a pit they'll take it off ya!! they will do tests that they have guide lines for and if it fits in to them they'll destroy it unless u can prove it isn't a pit.
have a look at
http://www.thekennelclub.org.uk/item...art/pg_ftr_art