mm-codepage-ibm-list

mm-codepage-ibm-list is a variable defined in `mm-util.el'.
Its value is

(437 860 861 862 863 865 852 850 855 866 857 864 869 874)

Documentation:
List of IBM codepage numbers.

The codepage mappings slightly differ between IBM and other vendors.
See "ftp://ftp.unicode.org/Public/MAPPINGS/VENDORS/IBM/README.TXT".

If an element is a number corresponding to a supported windows
codepage, appropriate entries to `mm-charset-synonym-alist' are
added by `mm-setup-codepage-ibm'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.