This is an acronym for Cock Devastation League, a group of men (and purportedly woman) who get their jollies by creating variations of the game "ring around the rosie".
Callum Defence League - St Mary’s hardest bunch of lads who pretty much run FY1 and FY2. No other group their age dare get in their way as they’re scared of the mythical one known as Callum Collier. Their main opps are known as ‘NWBF’
Her bad decisions are a result of having her CDL from the feminist movement and her over seer needs to keep her busy and stop giving her the leading role so his home isn’t a wreck.