Labels are a new feature in Mathad Prime 1.0 that allow you to assign different meanings to the same character. A label is a way of designating a math type such as variables, constants and units. A label allows you to format all units, say to a certain look.
We developed labels because sometimes you might want to use say "m" for a meter unit, but then that prevents you from using "m" for a variable. Labels allow you to do both.