https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125095
--- Comment #4 from anlauf at gcc dot gnu.org --- 13.11.3.6 Namelist comments Except within a character literal constant, a “!” character after a value separator or in the first nonblank position of a namelist input record initiates a comment. The comment extends to the end of the record and may contain any graphic character in the processor‑dependent character set. The comment is ignored. A slash within the namelist comment does not terminate execution of the namelist input statement. Namelist comments are not allowed in stream input because comments depend on record structure.
