Question: Handling of scientific sonstants

I understand that if I want to use a scientific constant in a Maple worksheet or document, I first have to declare it. Here is an example for the speed of light:

However if this worksheet is re-executed (e.g. using !!!) this happens:

Obviously there is a kind of recursion for c which is listed in the Variable Palette as a name for a variable but which is also the scientific constant. The problem can be solved e.g. by associating another name to the constant and unassigning the old definition in the Variable Palette:

This works but it makes the document harder to read since everybody is used to lowercase c for the speed of light. The same is of course true for other scientific constants.

Is there a way to use scientific constants in their "usual" notation in Maple, including using the unit of the constant?