Shibboleth Developers

We're probably about to begin registering some service providers 
within IQ. This will require the IQ administration to assign 
providerId values to these targets.... do people have thoughts on a 
default  approach for developing these values?

the two obvious options are:

1) url values. The shibboleth.xml file in the current distribution 
uses this approach. eg https://example.org/shibboleth/target

2) urn's.

Since every providerId that a service provider wants to publish to 
the world will have to be in the Federation metadata, it might be 
worth exploring whether/how IQ Admin might be able to delegate the 
authority for assigning providerIds within specific name 
spaces....... its likely, tho, that we don't have to resolve this in 
the short term.....