9.50.2.1 Special Characters ........................... Line comments are introduced either by the '!' character or by the ';' character appearing anywhere on a line. A hash character ('#') as the first character on a line also marks the start of a line comment, but in this case it could also be a logical line number directive (Comments) or a preprocessor control command (Preprocessing). The Visium assembler does not currently support a line separator character.