In the 1980's in Belfast, my Dad was registering to be a Doctor at City Hospital. On the form he wrote down for religion "none". He was then told he wasn't allowed to write none and had to chose something. They also wouldn't let him write down Atheist so he made one up and settled on "The light of the upper zarquon". For the next month nurses kept accosting him asking "Doctor Banks! What is this light of the upper zarquon?".
Growing up in northern ireland, I went on quite a lot of cross community (protestants mixed with catholics) trips. In order to get the numbers right they would ask me whether I was Catholic or Protestant and I would answer atheist. This wasn't good enough, they needed an answer so they would then ask what my parents were, so I also answered Atheist. Finally they would ask "What school did you go to?" to which I would reply "Wellington", "ahhh, so you're a protestant then...".