Stupid question - but I have to ask. As I tab through a worksheet and come
accross a certain cell, a popup message in a yellow box appears telling me
some useful info pertaining to that cell. How do you create or delete this
pop up?

This is not a "comment" box - I know how to do those, this is just a simple
pop up message. I would look in help but not sure what this is called? Any
guidance?