Besides these changes to the lead byte range, the other distinctive feature of the double-byte portion of Mac OS Chinese Simplified is the inclusion of two extensions to the basic GB 2312-80 set in rows 6 and 8. These are considered "standard extensions to GB 2312", neither of which is proprietary to Apple: the row 8 extension was taken from GB 6345.1, both extensions are included by GB/T 12345 (the Traditional Chinese variant of GB 2312), and both extensions are included by GB 18030 (the successor to GB 2312).