mark "file," because in context it didn't seem as if the argument was
being literally named. rather it seemed that the argument's purpose
being described. (the difference being: "... modification times of the
file named by file" would be a case where the the argument was named,
and thus be used with .Fa.)
high-order bit set", as this error is obsolete.
Eventually we may want to add code to some of the "optional" filesystems
(msdosfs, etc.) that checks for illegal characters. At that time it would
be appropriate to reintroduce this error with appropriate text. Perhaps
"The pathname contains a character that is not valid for filesystem type".
Use .Fn rather than .Nm macro in HISTORY and STANDARDS sections.
Use .At and .St macros instead of spelling out "Version 6 UNIX",
"IEEE 1003.1-1988 (POSIX)", etc.