This is a request for a codepage to be added in the next JDK 6 release. CP1364, is IBM's EBCDIC implementation that supports KS X 1005-1 (formerly KS C 57) although that particular standard did not specify CP 1364 in particular. CP1364 has been around for awhile, and according to HP this is a Korean National Standard.
The fixes for 6ux and openjdk7 are available, the webrevs are at
Sustaining will handle the 6ux (probably J4B, not 6u14) release, separate sub-CR can be created if necessary.
The decision is NO for jdk6/7, for now. Handover to sustaining team