The characters * and # are line comment characters; each
start a comment at the beginning of a line, but only at the beginning of a
line. A # prefixes a hexadecimal number if found elsewhere on a
line.
Two other characters, % and !, each start a comment anywhere
on the line. Thus you can't use the modulus and not
operators in expressions normally associated with these two characters.
A ; is a line separator, treated as a new-line, so separate
instructions can be specified on a single line.