Language Spec Comment: Importing Extension Profiles

The Language Spec currently defines "extension" and "extension_unr" fields within the Target, Actuator, Args, and Response tables in order to allow custom actuator profiles ("extensions") to define new members of these types.

It has been proposed to simplify the mechanism by which extension actuator profiles are imported, eliminating the dedicated extension fields and importing them in the same way that standard actuator profiles are imported.

In order to accomplish this without risk of namespace collisions, the OpenC2 TC will need to maintain an Actuator Profile Registry whose scope includes both standard and extension profiles, and all new profiles will be required to select namespace identifiers that have not previously been registered.