Labels may only exist in program memory; they make no sense in Run Mode. A label begins with the "
@" sign, followed by between 1 and 16 characters, which may be any combination of letters, numbers, and the underscore character. Unlike variable names, program memory labels can 'begin' with a digit (after the
@ symbol, of course). Labels are essentially case-insensitive, as variable names are: upon exiting Edit Mode (whether to Run Mode or Help Mode), every lowercase letter in every label (and variable name) is replaced with its uppercase.