A DESCRIPTION OF THE REQUEST :
Relations between charset names are given from different places:
- file standard-charsets
- class ExtendedCharsets
- file sbcs
- file extsbcs
- 'contains' relations are defined within discrete classes
- relations between canonical names and class names are defined within discrete classes
- historical names are partly held in classes, and partly in sbcs, extsbcs and dbcs

I sugest to define all mane relations from 2 files (to locate in make/tools/CharsetMapping):
- file standard-charsets
- file extended-charsets


JUSTIFICATION :
It would be much easier to maintain those names from central place.
There should not be redundant double-definitions.