On 07/03/2012, at 10:32 AM, Peter Saint-Andre wrote: > On 3/6/12 4:19 PM, Randall Gellens wrote: >> At 3:30 PM -0700 3/6/12, Peter Saint-Andre wrote: >> >>> In my working copy I've changed that paragraph to: >>> >>> Implementations of application protocols MUST NOT programatically >>> discriminate between "standard" and "non-standard" parameters based >>> solely on the names of such parameters (i.e., based solely on >>> whether the name begins with 'x-' or a similar string of characters). >> >> I like this wording, especially because it more clearly gets at the >> heart of the document, which is to not discriminate based only on the >> name prefix. >> >> One question, though: should this be "SHOULD NOT" rather than "MUST >> NOT"? The interoperability doesn't depend on implementations >> refraining from doing so, rather, we consider it more problematic to do >> so than not, so we are making a strong recommendation to not to so. >> Hence, "SHOULD NOT". > > Hi Randall, > > My co-author Mark Nottingham feels even more strongly about this issue > than I do, so I will let him comment. To me, the target of that language is software that generically treats protocol elements beginning with "x-" in a fundamentally different way, without knowledge of its semantics. That is broken, causes real harm, and I have seen it deployed. Regards, -- Mark Nottingham http://www.mnot.net/ _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf