[html4all] Grandfathering ?

[Philip TAYLOR (Ret'd)]

I have little or no understanding of the underlying
issues concerning table headers and IDs, so I have
steered well clear of this discussion, silently
siding with any and all suggestions that can
improve the accessibility of tables.  However,
in trying to catch up with the thread, I encountered
the following from Henri :

> In the part of my email you didn't quote, I said I was in favor of grandfathering headers/id into the spec.

Could anyone (I imagine it would have to be a native
<Am.E> speaker, since I don't believe the verb exists
in <Br.E>) explain what "to grandfather" is, please ?

Philip TAYLOR