-/* If this bit is set, assume unprintable characters have width 1.
- Otherwise, return -1 upon finding a non-printable character. */
-#define MBSW_ACCEPT_UNPRINTABLE 2
+/* If this bit is set, return -1 upon finding a non-printable character.
+ Otherwise, assume unprintable characters have width 0 if they are
+ control characters and 1 otherwise. */
+#define MBSW_REJECT_UNPRINTABLE 2