Subject: Protocol: Ignore SEQUENCE elements...

From: "Jim Sermersheim" <[email-masked]>
Date: Mon, 14 Jul 2003 15:16:38 -0600

All,
 
There is the statement in [Protocol] that instructs:
"Because of the implied extensibility, clients and servers MUST ignore
trailing SEQUENCE elements whose tags they do not recognize."
 
This is basically the same text as RFC2251 (we added the _why_, and the
word "trailing").
 
But I think this falls short of what it really intends to say. I think
that what it really intends to say is that:
"protocol peers MUST ignore the presence of arbitrary unexpected
extension additions above those defined (if any) in a SEQUENCE or SET
type, or of an unknown alternative in a CHOICE type, or an unknown
ENUMERATION in an enumerated type, or of an unexpected length or value
of a type whose constraint is extensible."

I just stole most of that from X.680, thus it could be shortened with a
reference, but I think the information might be handy. Also, we should
likely preserve the "trailing" word.

a) Am I basing this on some false assumption/information?
b) Do we want to make this change?

Jim