See, puns are meant to "break the ice", and they're indeed (at least for the most part) made in serious situations. I went to a convenience store once and there were two signs:

[![no checks allowed][1]][1]

I have nothing against Czechs I use them to pay for some stuff, but I hate checks, don't punish me, I'm not racist, but I made you snigger though!

  [1]: https://i.sstatic.net/oMW1i.jpg