Working in a public library means that I have the opportunity to work with people having different levels of technological know-how. I've had users ask "Mouse? Isn't that a rodent?" and others asking "How do I code an app?" There is a pretty vast range of computer knowledge in our patron base and as a library worker it is my job to meet users at their level and be able to communicate and assist them on that level.
Sometimes, this means saying PIN Number because a patron might not know or understand what a PIN actually is.
As with any opportunity to teach, I use these interactions to explain what a PIN actually is or to help familiarize the patron with the program or internet browser they are using. One of the most rewarding parts of working with the public is being able to give them knowledge they didn't have before and the ability to use that knowledge.
So, do you say PIN or PIN number when talking to the public?