This isn't a subject I'm likely to start foaming at the mouth about! Surely the "square" ones have rounded edges so are not even square.
Didn't Ind Coope Burton Ale do some large oval ones or is that a memory management violation?
Oval with "ears" at the corners, two sets of them were produced around 1980.
Tell us, now, how and when
We may find the bravest men?
A sure test, an easy test:
Those that drink beer are the best