I haven't been at my current job (an accounting firm) for all that long, but a funny thing happened the other day (although I didn't think it was so funny when it happened).
Anyway, to get to the story, a few months ago, when my co-worker was showing me the proper procedure for sending/giving forms to clients, she instructed me to fill out these pre-printed little slips and paperclip them to the form, so the client would know what to do with the form. They tell clients what the form is, whether to sign, who the payee is, and when it's due. When she showed me what to do with them, she referred to them as "idiot slips," kind of in the same line of thinking as "idiot lights" I guess. So, every time I needed to refer to these slips or thought about or saw them, I thought "idiot slips."
Well, we get a debit memo that a particular client has not sent the required payment with a particular form. I call the client and we chat about the situation for a moment, and the thought occurs to me that I might have accidentally put nothing as the dollar amount due on the "idiot slip." My co-worker/boss is doing something else next to me, so she can hear our conversation. Without thinking, I say, "Well maybe I didn't put a payment on the idiot slip." *GASP* ... As soon as I say "idiot slip," I realize I've screwed up yet again! Thank God he was a nice guy/client on the other end. The comment didn't seem to bother him at all, but after a moderate pause, while looking at my boss shaking her head in a manner of disgust, I came around from the initial shock and said, "not that you're an idiot!!" I went on to explain how people are simply supposed to follow the forms exactly to fill those out...but that perhaps I screwed up the form, etc. Heh, needless to say, those are "instructional slips" from now on. :)