2.1. Organization of Registries

2.1. Organization of Registries

All registries are anchored from the IANA "Protocol Registries" page:

https://www.iana.org/protocols

That page lists registries in protocol category groups, placing related registries together and making it easier for users of the registries to find the necessary information. Clicking on the title of one of the registries on the IANA Protocol Registries page will take the reader to the details page for that registry.

Unfortunately, we have been inconsistent in how we refer to these entities. The group names, as they are referred to here, have been variously called "protocol category groups", "groups", "top-level registries", or just "registries". The registries under them have been called "registries" or "sub-registries".

Regardless of the terminology used, document authors should pay attention to the registry groupings, should request that related registries be grouped together to make related registries easier to find, and, when creating a new registry, should check whether that registry might best be included in an existing group. That grouping information should be clearly communicated to IANA in the registry creation request.