Getting prompted to enter a variable when there is no ampersand (&) in the code -- what else causes

I select my pl/sql and click 'execute as script' and I get prompted for   &P    

I searched for ampersands ( & )  in my code and there are none.  The word prompt isn't in there, either.  What other things can cause you to be prompted to enter variables?

Thanks for your thoughts!

J