-#define LEADING_BYTE_HIRAGANA_JISX0208 (CHARSET_ID_OFFSET - 4)
-#define LEADING_BYTE_KATAKANA_JISX0208 (CHARSET_ID_OFFSET - 5)
+/* MULE VISCII-LOWER (CHARSET_ID_OFFSET_96 + '1') */
+#define LEADING_BYTE_LATIN_VISCII_LOWER (CHARSET_ID_OFFSET - 4)
+
+/* MULE VISCII-UPPER (CHARSET_ID_OFFSET_96 + '2') */
+#define LEADING_BYTE_LATIN_VISCII_UPPER (CHARSET_ID_OFFSET - 5)
+
+/* Big5 Level 1 2/4 2/{(8),9,10,11} 4/0 '0' */
+#define LEADING_BYTE_CHINESE_BIG5_1 (CHARSET_ID_OFFSET - 6)
+
+/* Big5 Level 2 2/4 2/{(8),9,10,11} 4/0 '1' */
+#define LEADING_BYTE_CHINESE_BIG5_2 (CHARSET_ID_OFFSET - 7)
+
+#define LEADING_BYTE_HIRAGANA_JISX0208 (CHARSET_ID_OFFSET - 8)
+#define LEADING_BYTE_KATAKANA_JISX0208 (CHARSET_ID_OFFSET - 9)