4.13. Provisional Registrations

Some existing registries have policies that allow provisional registration: see URI Schemes [RFC7595] and Email Header Fields [RFC3864]. Registrations that are designated as provisional are usually defined as being more readily created, changed, reassigned, moved to another status, or removed entirely. URI Schemes, for example, allow provisional registrations to be made with incomplete information.

Allowing provisional registration ensures that the primary goal of maintaining a registry -- avoiding collisions between incompatible semantics -- is achieved without the side effect of "endorsing" the protocol mechanism the provisional value is used for. Provisional registrations for codepoints that are ultimately standardized can be promoted to permanent status. The criteria that are defined for converting a provisional registration to permanent will likely be more strict than those that allowed the provisional registration.

If your registry does not have a practical limit on codepoints, perhaps adding the option for provisional registrations might be right for that registry as well.