In the Korean encoding KS C 5601-1987 some CJK ideographs appear several times by design. It is to accomodate multiple readings of these character in Korean. Unicode requires a set of these characters for full round-trip mapping between the two different standards. There are 268 characters belonging to KSC, the first at U+F900 (63744) and the last at FA0B (64011)
There are a number of other characters included in this section which have other origins.
2 characters belong to Big5 U+FA0C (64012) and U+FA0D (64013).
32 characters for IBM compatability additions. 12 of these are not encoded within the main CJK Unified Ideographs. The others are considered as variant forms of existing characters. Those 12 characters are distributed throughout the 32 character block.