When I looked at clubs from Canada, the UK and even here in the USA I found that some were very receiving regardless of agency affiliation and others were very shall I say selective. The most common thing I saw in regards to an agency thing was the esprit de corp most of it was of a light nature of jestering. There were those who appeared blinded to only one agency having supremacy, for the most part they were ignored. The second most common thing was the need from some club divers who felt the new diver had to prove themselves. I suppose this is a trait of human nature. Truthfully, usually the better divers never fell prey to this and those who sought this higher than thou need of one upmanship made dives only within their ilk