On Aug 15, 2013, at 1:19 PM, Yaron Sheffer
<yaronf(_dot_)ietf(_at_)gmail(_dot_)com> wrote:
I am quite sure that I fully understand the semantics of "critical" (probably
erroneously), so I'm not the right person to clarify the various meanings of
the word. I would appreciate a proposal.
Just for the record, my "critical" means: the reader must be able to process
the data item according to its specification, not just syntactically but also
semantically, and must fail otherwise. There may still be contained
non-critical data items that are NOT understood by the reader.
And what you say should happen if a decoder saw the One True Critical tag
before an array item, and then the decoder soon thereafter finds a tag it does
not know about? The "critical" tag was on the array, not on the unknown item.
And so on. We've been there, and we haven't done that so well.
Sec. 2.4 consistently mentions "tag" in the singular. For example, the first
sentence could be "a data item can optionally be preceded by one or more
tags" - but it isn't.
A tag is also a data item. A tag refers to the next data item, even if that
next data item is also a tag. We'll try to clarify this in the -06.
--Paul Hoffman