[Nml-wg] Identifiers

[Jeroen van der Ham]

On 7 nov. 2010, at 20:23, Freek Dijkstra <Freek.Dijkstra at sara.nl> wrote:

> My own opinion below.
> 
>> Question 1. Should the schema end with a / or #?
>> a) http://schemas.ogf.org/nml/base/2013/10   (common for XML)
>> b) http://schemas.ogf.org/nml/base/2013/10/  (current proposal)
>> c) http://schemas.ogf.org/nml/base/2013/10#  (common for RDF)
> 
> Either b or c. (a may be a problem for RDF).

B seems to be the most interoperable solution.

> 
>> Question 2. What attributes to use for references in XML?
>> a) existing id and idref in NM-WG namespace
>> b) redefine id and idref in NML namespace
>> c) create dedicated namespace for just id and idref
> 
> No big prefence. In order: a, c, or b
> (b lowest preference because I don't want to redefine again if we create
> technology-specific schemata,. e.g. for Ethernet, OTN, IP, etc.)

I thought we decided on B?
To me it seems very weird to reuse NM-WG namespace for something trivial as this and for that reason almost ridiculous to create a dedicated namespace for that.

> 
>> Question 3. What characters are allowed in <opaque string>?
>> a) GLIF:       A-Z a-z 0-9 - .
>> b) unreserved: A-Z a-z 0-9 - . _ ~
>> c) RFC2141:    A-Z a-z 0-9 - . _ ( ) + , : = @ ; $ ! * ' %hex
>> d) pchar:      A-Z a-z 0-9 - . _ ~ ( ) + , : = @ ; $ ! * ' & %hex
> 
> Whatever will be defined in rfc2141bis, thus d or c.
> a or b miss a : and are too limited for that reason.

I think we implicitly decided on C when we discussed the UTF-8 discussion...
IIRC, we decided to follow the RFC syntax for urns. 

> 
>> Question 4. MUST all object have an id?
>> a) All Network Objects MUST have an identifier.
>> b) All Network Objects SHOULD have an identifier.
> 
> b. Use it unless there is compelling reason not to.

No real preference, but I can see that in some cases you don't want to do that.

> 
>> Question 5. MUST urn:ogf:network syntax be used?
>> a) All identifiers MUST follow the urn:ogf:network syntax
>> b) All identifiers MUST be a URI, and SHOULD follow the urn:ogf:network
>> syntax
>> c) All identifiers MUST be a unique, and MAY follow the urn:ogf:network
>> syntax
>> (some more variants are possible)
> 
> b. Use it, unless there is compelling reason not to. Allow other syntax
> for forward compatibility. (e.g. I can imagine that in the future
> instead of using the FQDN or AS number, we have another method to
> identify domains, and we allow another type of URN).

Why do we want to restrict IDs to the urn namespace?
IMO we want to have only one restriction: the ID must be globally unique, and it is up to the originator to come up with one that can be reasonably expected to be unique.
The urn syntax makes it easy to do that, but other resources that are described in RDF may end up in a network topology description in some way, and these will not always use that syntax.
I guess that means I vote for C. 

Jeroen. 
>