Clarify D in req/core/identifier about wcmp2 HOT 5 OPEN

@tomkralidis

from wcmp2.

Perhaps we can further qualify with:

• no spaces
• no accents
• no colons (given they are URN separators)
• none of the following: `~!@#$%^&*()=][{}|'";,.?/+

cc @josusky

from wcmp2.

This is too restrictive. The regular expression that you have provided is correct only for the "namespace identifier" NID part. But the NID is fixed in our case to wmo. The rest of the URN is "Namespace Specific String" (NSS) and its validation is more benevolent. Original description is in https://www.rfc-editor.org/rfc/rfc2141.html (section 2.2) and is slightly modified (extended) by newer RFC (https://www.rfc-editor.org/rfc/rfc8141). Example of a valid URN is:
urn:example:a123,z456?+abc

from wcmp2.

I am not deadly against a rule that is more strict than actual URN specification. I looked up the specification because I spotted the innocent dot (.) in Tom's list - that "lifted me off the chair" :-)
I can hardly imagine anyone putting ~ or ] into metadata ID but a dot (.) or slash (/) seem quite OK to me.

from wcmp2.

Having a slash (/) in the ID introduces URLs like the following in the GDC:

https://example.org/collections/foo/items/foo%2Fbar

While we can relax the regex set mentioned previously, the above would be error prone.

from wcmp2.