>The problem is that often when an index is corrupted, it's header and
>therefore its very definition is corrupted. Without meta data stored external
>to the dbc and cdx, a RECREATEINDEX routine can't do its job dependably.

Corrupted indexes isn't the only ones that need to be recreated! For instance, changing a tables' codepage, will need a recreate of all index tags for the tags to respect the new codepage.