From Tapestries MUCK
Each object has an ID number (the 'dbref'), which appears after the name of an object, and is followed by any flags on the object; i.e. foo(#3672PM) is a Player, MUCKER, named foo, with a dbref of #3672.
This number is a database reference, and is used to specify objects at a distance; i.e. examine #<room ID number>.