> The BNF is revised:
Thanks for that!

In this e-mail, I will just write a few short comments. I plan to write 
about some bigger issues later in their own thread.

> BNF syntax used

Maybe we should clarify that

(A B) | C

means the same that

A B | C

even without line break, doesn't it?

Several productions exclude negative years. Maybe, that is what we want. I 
suggest to clarify this point.

> Uncertaintly
may be misspelled at several places as well as

> internalUncertaintOrApproximate

Furthermore, I can not find the production with

> dateWithInternalUncertaintly

on its LHS.

A problem in today's BNF is that it allows dates such as


and I consider that this needs to be fixed.