- ignoring case, returning less than, equal to or greater than zero if this
- initial segment is lexicographically less than, equal to or greater than
- PREFIX.
- Note: This function may, in multibyte locales, return 0 if STRING is of
- smaller length than PREFIX! */
+ ignoring case. If the two match, return a pointer to the first byte
+ after this prefix in STRING. Otherwise, return NULL.
+ Note: This function may, in multibyte locales, return non-NULL if STRING
+ is of smaller length than PREFIX! */