Actually, the current spec is very ambiguous about white space in general, and leading white space in particular (which I don't think is mentioned). And as far as I know it makes no mention of the first line being special. That said, the LSC discussion is leaning towards the following rules:
- Space and tab are the only allowed white space characters, and they must be treated the same.
- All parameters on every line must be separated by one or more white space characters.
- All leading and trailing white space characters around the filename portion of a type 1 line must be ignored.
- Any number (0 or more) of white space characters are allowed at the beginning of any line in the file, except:
- If the file contains a title (first line is a comment line), that line must not contain leading white space. (Note that part files are required to start with a comment line that is used for their title, so this means that the first two characters of all part files must be 0 followed by either space or tab.)
- If the file contains a title (first line is a comment line), that line must not contain leading white space. (Note that part files are required to start with a comment line that is used for their title, so this means that the first two characters of all part files must be 0 followed by either space or tab.)