The Visual LISP code formatter can make it easy to distinguish between protected and unprotected AutoLISP symbols.
An AutoLISP symbol can be a variable or function name.
You can set the code formatter to change the case of symbols according to their protection state. You can choose to not change the case of a protected or unprotected symbol, or change the symbol to all lowercase or uppercase letters. Case changes occur when either the Format Edit Window or Format Selection tools are used.