"Registering" a schema

[ebwinters]

The following statement in the schema section of the tutorial is confusing

Anybody can create a new schema using the Lexicon language, which is very similar to JSON-Schema. The schemas use reverse-DNS IDs which indicate ownership. In this demo app we're going to use xyz.statusphere which we registered specifically for this project (aka statusphere.xyz).

What does registering a schema mean? Is it just confusing wording, or do we really need to contribute some schema to the PDS we plan to publish events to (in this case Bluesky)?