How is the character encoding identified based on the ISO standards listed as valid values?
Valid values for ISX02 are 1 - 16.
1. The value 14 = ISO 2022 BUT this breaks down into several specific character encoding (2022-JP, 2022-JP-2, and 2022-KR).
2. The value 16 = ISO 10646 and also breaks down into specific character encoding (UTF-8 VBCS, UTF-16 DBCS, UTF-32 (32 bit).
With UTF-16, this can be big endian/little endian and so how can it be determined that the GS/GE in an interchange is UTF-16 big endian if the value is 16 which equals ISO 10646.
With other ISO standards, identification for use in the ISX02, the specific encoding has specific value for example ISO 8859 which has values (4-13) to identify Latin-1, Latin-2, etc.
X12 recognizes that there aren't enough code values for ISX02. X12C will submit maintenance requests to add values.