Next, detailed information booklets were delivered to all households in the area (including many on the fringe who may have been receiving their TV from other transmitters- hence the importance of the on-screen warning captions). Two or three months later, the first stage of the switchover began with the analogue BBC Two replaced with the new BBC A multiplex. At some locations, during the period between stage one and stage two, BBC One, ITV or Channel 4 moved to the analogue BBC Two frequency where that channel's frequency was required for the digital transmission of Multiplex 1. At the same time, captions appeared on the remaining analogue channels reminding viewers of the impending switchover. Finally, the second stage saw the remaining analogue transmissions switched off and the other high power multiplexes switched on. Initially, this occurred four weeks after stage one, but starting with the switchover at Mendip in April 2010 onwards, this gap was reduced to two weeks.