Windows code page 1253 ("Greek - ANSI"),[1] commonly known by its IANA-registered name Windows-1253[2] or abbreviated as cp1253,[3][4] is a Microsoft Windowscode page used to write modern Greek. It is not capable of supporting the older polytonic Greek.
It is not fully compatible with ISO 8859-7 because a few characters, including the letter Ά, are located at different byte values:
µ[a] and ¶ are added at their locations from Windows-1252 and ISO 8859-1 (0xB5 and 0xB6). This collides with the locations of ΅ and Ά, respectively, in ISO 8859-7.
‘ and ’ are moved from their ISO 8859-7 locations (0xA1 and 0xA2) to their Windows-1252 locations (0x91 and 0x92). The displaced ΅ and Ά are moved to the vacated space at 0xA1 and 0xA2 respectively.
¤ and ¥ are added at their locations from Windows-1252 and ISO 8859-1 (0xA4 and 0xA5). This collides with additions made to ISO 8859-7 in 2003, when € and ₯ respectively were added to the same locations. The € was added to Windows-1253 at 0x80, the same location which it was added to in Windows-1252. An iota subscript (ͺ) was also added to ISO 8859-7 at 0xAA; this remains unallocated in Windows-1253.
Several further characters are added at their Windows-1252 locations, although the rest do not collide with ISO 8859-7.