Labels are identifiers that you use to tag the locations of program and data objects. Each label is composed of an identifier and a terminating colon. The format of the label field is:
identifier : [ identifier : ] ...
The optional label field can only occur first in a statement. The following example shows a label field containing two labels, followed by a (M68000-style) comment:
var: VAR: | two labels defined here
As shown here, letters in identifiers are case-sensitive, and both uppercase and lowercase letters may be used.