Syntax validation of articles by injecting agents

[Julien ÉLIE <[e-mail]>]

Hi,

RFC 5537 mentions that an injecting agent MUST reject any proto-article
that is not syntactically valid as defined by RFC 5536.

What is the best way to do that then?
Is it safe to implement that requirement?  RFC 5536 is said to
"reflect current practice", but if we enforce that MUST, I believe
it will break lots of news readers.

NN for instance does not generate MIME-Version: header fields
although "user agents MUST meet the definition of MIME conformance"
("a mail user agent that is MIME-conformant MUST always generate
a "MIME-Version: 1.0" header field in any message it creates").
I believe this sentence applies to news user agents too, otherwise
a reference to MIME is useless.


And what if a news reader generates an incorrect User-Agent: header
field?  or if it always adds a tail-entry which is not a path-nodot
in Path:?  All its posts will be rejected by a RFC-compliant injecting
agent...
It it the intention?

I quite understand that it would help to have better compliant
articles.  For instance, rejecting articles with "all" in their
distribution list.

But in some cases, people would need to upgrade their news
readers...  (and maybe change their news readers if it is
no longer maintained)
Or news admins will not be willing to upgrade to a news server
that is RFC-compliant.  (Unless syntax checks can be deactivated
but then, news admins will deactivate them, and the duty of
injecting agents will be useless -- "it bears much of the burden
of diagnosing broken posting agents or communicating policy
violations to posters".)

How can we handle that MUST without hurt?

-- 
Julien ÉLIE

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