A server configured with several handle domains only told the signup form's reader about the first: "Your handle will be .dids.lol". The handler already took a typed full handle as-is, so alice.dads.lol worked, but nothing on the page said the other domains existed.
With more than one domain the hint now reads "Your handle will be .dids.lol. To use thegem.city, dads.lol or atproto.camp instead, type the full handle, like alice.thegem.city." One domain keeps the old sentence and none keeps the prompt for a handle the holder controls.
The hint and the handle composition move into sign_up_handle_hint and sign_up_handle so both can be tested without a live signup, and the stale comment claiming a full handle would be refused is gone.
Refs bard#vd1t.