While searching for Antarctica info I discovered many sources with CE9 prefix assigned to Antarctica. Unfortunately CE9 is used also for South Shetlands. Other prefixes are also ambiguous (R1A, KC4, LU/Z, VK0, VP8 etc.). It seems most likely that only unambiguous prefix assigned to Antarctica is ZL5 and FT#Y (# = any number), however ZL5 seems more easy to handle. Therefore all my records of Antarctica were changed to ZL5.