I can understand that there are times when discretion may mean that silence on certain subjects is sensible. For example, speaking in support of the IRA in a pub frequented by the Orange Lodge, or singing The Sash My Father Wore in a Republican pub would only be a great idea if you like hospital food - or can run very quickly. The same applies to praising a football team in a pub associated with hostile supporters of a rival team.
Religion isn't something I discuss very often, but a few months ago I was talking in my local about how I had dealt with some religious door knockers. The two fellows on the next table interrupted me to say that you weren't allowed to talk about religion or politics in pubs. I think I replied, "Says who?" In the end they moved away to another table, which I thought was a laughable reaction: not only had they been listening in to our conversation, but they'd also missed the point: I hadn't been talking about religion, but how I had got rid of religious cold callers. Their attitude was interesting, seeing how much money the Salvation Army raises by collecting in pubs without there ever being the slightest murmur of objection.
Apart from my previous examples where avoiding certain subjects is simple self-preservation, who decides these rules, and why? I know some people say that their political allegiance is a secret between them and the ballot box, an attitude I used to gently mock by saying the same thing while wearing a political party badge; while that's fine for them, why does their reluctance to discuss something mean no one else should either? I find treating politics like a guilty secret quite odd, seeing how comprehensively it affects our everyday lives.
I've been trying to think of any subject that should automatically be out of bounds in pubs, but I can't. I find talk about sport boring, but that's only because I'm uninterested in sport; I wouldn't ban such talk, not that there'd be much chance here in Merseyside.
In case anyone thinks I spend all my time in pubs spouting politics, I don't. I simply can't see why some people consider it a taboo subject.