Re: [apps-discuss] draft-saintandre-xdash-considered-harmful-01

[Joe Hildebrand <[e-mail]>]

On 10/25/10 11:08 AM, "John C Klensin" <[e-mail]> wrote:

> Ignoring the obvious small issues with syntax, using
> vnd.URI.field-name or vnd.FQDN.field-name would have the
> advantage over vnd.Registered-Vendor-Name.field-name of not
> requiring an IANA registry... and the disadvantage of being
> somewhat less stable.  Of course, we could punt that tradeoff by
> having both Registered-Vendor-Name and something URI or
> DNS-based with different first-facet prefixes and letting the
> vendor choose between long-term stability and the convenience of
> avoiding dealing with IANA at all.

For syntax, base64 generates sequences that are valid according to the
field-name production of 5322.  Clark notation is a nice fit for the
URI/field tuple.  As such, this should work:

"B64-" + base64({uri}field-name) + ": " + value

The person/group that owns the URI owns the change control over that
uri/field tuple, and is responsible for forward- and backward-compatibility,
or changing the uri or field for incompatible changes.

The B64- prefix is intended to ensure that we don't overlap an existing
header by mistake, and to give a hint to third parties that if they
base64-decode the field name, they should get something interesting.

-- 
Joe Hildebrand