Context Rules 2/2 - A broader question

[Chris Wright]

ISSUES WITH CONTEXT RULES THAT ARE FOR REGISTRATION ONLY

Firstly I'd like to support Shawn Steele in his view that these should be described more like:

> Maybe instead of "Lookup: true/false" it could be something like "Context: Registration Only" or "Context: Registration and Lookup".

We assume that the audience of these rules is for humans and this clarifies things very clearly.

However, I'd really like to ask what is the purpose of Registration only context rules. Given that these rules won't stop domains being looked up as soon as a registry disagrees with one of the registration only rules, they will simply stop applying it!. For example the context rule concerning 'modifier letter prime' discussed above which excludes a hyphen or digits, why would I as a registry operator want to apply it as written? If I allow hyphens to be used in those names, the domain names will still work when looked up. This leads me to a greater discussion about how registration only context rules are really just policy decisions!

I acknowledge and welcome the effort put in by all, and I think they are important aspects of IDNs that should be documented and circulated, however, I feel they are only implemented by registries and thus should only be recommendations for best common practices for registries, not enforced parts of the standard/protocol/<insert the right word here>. The document should be educating the registries about the potential issues with certain characters that they may allow but that should be it. Not all languages have been represented during the development of these rules, what if some language that has not been considered yet requires to use this 'modifier letter prime' (or some other focus of another context rule) and we have now FORCED with the protocol that they couldn't, when really it should just be a recommendation for the zone administrator (registry) about a business rule they should apply to registrations. I believe there will potentially be many more 'context' style rules that will need to be developed as we move forward, and these will not become part of the standards documents, just be rules that are implemented by registries.

As an example, if we look at the 'Yiddish' rules used by the .SE registry (documented here http://iana.org/domains/idn-tables/tables/se_yi_1.0.html) they state that certain combining marks are only allowed to be used with certain base characters (i.e. in a given context), these are also 'context' rules but not things that should be part of the standard. As long as the code points are PVALID, and if this means some code points become PVALID by exception then so be it, but then leave it the registries to define the contexts in which they actually can and can't be used.

A BCP document that points out the issues with each item context rules are trying to address, shows some examples, and then recommends that zone administrators produce policy requirements to prohibit certain registrations using context style rules should be sufficient, and is the most flexible approach moving forward. No zone administrator in their right mind would do anything to risk their namespace being branded as unsafe etc. I also believe that lower levels of DNS hierarchy will never apply 'registration only' context rules!

Thanks

Chris