-/* Assume invalid characters have width 0. If this is zero, the
- functions return -1 if they find an invalid or incomplete character. */
-#define MBSW_ACCEPT_INVALID 1
+/* If this bit is set, return -1 upon finding an invalid or incomplete
+ character. Otherwise, assume invalid characters have width 1. */
+#define MBSW_REJECT_INVALID 1
+
+/* 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