Registration and flight number for regional jets?

I noticed some time ago that you put in an airline’s aircraft registration like N633DL and it’ll show N633DL/DAL123. But when ever I type in a regional jet’s reg it does not appear it only has the registration information. Is this something new or still in progress?

We don’t yet have the tail number to flight number mapping working for all airlines, but we’re moving in the direction of improving it.