Quoting [Gary Mazz] (Oct 07 2010):
Great work adding tags into the collections.
Adding tags may be two edged sword. They allow "folksonomy" a path into occi, but tags may be used by providers to represent technical aspects of their infrastructure. This could be catastrophic for interoperability. For example, a provider elects to use tags to represent an OS instead of a template. As/if this practice continues, we may end up with tags de jour, crippling interoperability and devaluing formalized extensions.
We can minimize the impact by limiting tag usage to informative metadata, not impacting resource provisioning or operations. This would encourage providers to use extensions and provide a taxonomy for extension impacting interoperability.
+1 One should check the use cases if this limitation is practical though. -- Nothing is ever easy.