Tables: BackwardCompatible Maintanence

[Kenneth Whistler]

Mark asked:

> Patrick asked about consensus for this item. I don't want it to fall through
> the cracks, so would anyone object to a change?

And I certainly do not object to his proposed change.

The maintenance of BackwardCompatible is not optional.
It should be clearly mandated in the document, with
better wording under Section 2.7 in idnabis-tables.

--Ken