The names students bestow their flats with are often full of wit and humour. The sign for Bedrock is made using a single bedhead. The name may be related to the popular cartoon series The Flintstones where Bedrock is the prehistoric city where the Flintstone and Rubble families live. The name may also refer to beds rocking due to sexual activity. The use of a bedhead as the board for the sign implies this may be the case.  It’s not often that the name of the flat and the sign riff off each other to add another layer of meaning.