[eppext] VAT / National identifier (Was: [IANA #826994] Registration request for EPP extension)

[Alexander Mayrhofer <[e-mail]>]

> Von: EppExt [mailto:[e-mail]] Im Auftrag von Patrick
> Mevzek
> Based on the (mostly ccTLDs) EPP extensions I have seen working with
> this kind of data, I was planning to write after the Stockholm EPP
> workshop an extension to handle that,
> and then starting the hard part on seeing how it could get implemented
> by registries…

As i mentioned during the Stockholm meeting, i think the "proper" approach to all those "external identifier" problems could be an extension that allows for association of:

  - identifier "type"
  - identifier "value" 

For registry objects. For identifiers which have already an URN namespace, the "value" could then be an URN (in which case the "space" descriptor would probably not be needed). An example could be

<referenceID type="vat:at">ATU2423424324</referenceID>

or

<referenceID type="ssn:fi">PERSON34534XTZ</referenceID>

We would then, though, probably need a "meta-registry" with to register all the possible "types" and definitions for those. 

> I have not started that work yet, and if anyone has ideas and/or want
> to help write the I-D, he/she is welcome.

A first step could be to collect the various use cases of external identifiers used in registries. I think a large a-z Registrar would be the prime candidate for providing most of the information, because they typically have the best  "market overview".

Though, as always, there's the tradeoff between flexibility and ambiguity when starting to define a "key / value" type extension...

Alex