I just remembered, some time ago nearly 50 years back I was doing some work for a chap that was a Belgian he asked me to fit a replacement cock-spur on to his casement window for him, he said to me I'm not sure if this one is the right hand for the job, I then regressed back into the family use of bifocal, it just came out and I said to him "oh don't worry they're bifocal", Belgians, they're supposed to lack a sense of humour and unfortunately it was true in this case, he then spent time explaining to me that I didn't really mean bifocal and all of the rest, I couldn't say to much because of the size of the contract involved, the customer's right even when they're wrong philosophy clicked in
Regards ippy