[Edit: in reply to Séan]:
Sorry, I was going to post more, then left that line, then deleted it.
As for the definition in question, yes we do cask our beer, and I am a big fan of cask ales, but we also selectively install cask breathers - on a case by case basis depending on turnover in each pub. Now we have a situation where, by CAMRA's definition, one pub is serving real ale, while the one across the road is not.
Thankfully the average beer drinker, and Beoir, do not have such tight guidelines, and people can just enjoy cask ale for what it is.