DEF II was a programming strand on BBC Two, which aired at 6pm on Mondays and Wednesdays from 9 May 1988 to 23 May 1994, to serve the teenage market. It was produced by Janet Street-Porter, and followed on from her influential youth TV show Network 7, on Channel 4. In fact, many of the presenters and staff on DEF II started their careers on Network 7 and had followed Street-Porter when she was "poached" by the BBC. It had an ident featuring a barcode which differed from the usual idents used on BBC Two.