tain upper and lower
case letters, digits, underscores, and periods. The first character must
be a letter or the local label prefix (default '_'). The value of a label
is limited to 32 bit precision. Labels can contain up to 32 characters,
all of which are significant (none are ignored when looking at a label's
value, as in some assemblers). Case is significant unless the '-i' command
line option is invoked.

<P>Local labels must only be unique within the scope of the current module.
Modules are defined wit