The reports I refer to are word of mouth mostly. Idle chatter over IMC, on forums from time to time, mentioned in passing in email, or even fixed in our other projects long ago and simply forgotten about. There is no database of unreported bugs here.
The closest to that would be a post for a fix which hasn't been included, so you could I guess call those unconfirmed bugs
BTW, I do try and keep track of such things when I have time by visiting other related forums such as Remcon's LoP site, MudBytes, TMC, TMS, MUD Planet, Gammon's forums, and yes, I even dirty myself from time to time by checking posts in the Smaug section at Mudmagic. If there's a report of a bug that hasn't been covered, I'll usually make a note of it. I'm sure others do the same by noting fixes in their own projects and bringing them here as well.
This forum happens to be the most active forum specifically dedicated to Smaug, so most stuff seems to be getting reported here first anyway.