I have, accidentally, paid in two 'unusual' cheques.
One had the payee's name completely blank - I was meant to write that in myself, to save the hassle of them struggling to spell it - then I forgot.
The other was not signed at all - I noticed this and I meant to get them to sign it, but then it got paid in by accident with another cheque - I realised the next day and confessed to the counter clerk who I had paid it in through - "We'll see if anybody else spots it and then sort it out, if they do" - nobody did.
I frequently pay in cheques with variations of the spelling of my name.
Paying stuff in at another bank, for someone else, the chap in front of me was asked to sign a form - "Which signature should I use?", he asked the clerk, who was a bit stuck for an answer...