https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114304
--- Comment #20 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> --- Some additional information from the 2023 standard. 13.10.3.1List-directed input forms 8 If the next effective item is default, ASCII, or ISO 10646 character and • the character sequence does not contain value separators, • the character sequence does not cross a record boundary, • the first nonblank character is not a quotation mark or an apostrophe, • the leading characters are not digits followed by an asterisk, and • the character sequence contains at least one character, the delimiting apostrophes or quotation marks are not required. If the delimiters are omitted, the character sequence is terminated by the first blank, comma (if the decimal edit mode is POINT), semicolon (if the decimal edit mode is COMMA), slash, or end of record; in this case apostrophes and quotation marks within the datum are not to be doubled. --------------------------------------------------- I am still digesting this and should have something sorted out in the next day or so.