This feature uses a capability of the open Decentralised Identity standards called Verifiable Credentials (see Verifiable Credentials 101 for more information about how they work).
Decentralised Address Name Registrars will issue a Verifiable Credential stating that a DID is the owner of a specified address name. DARP compliant applications can use the Verifiable Credential to ensure it is using the owner's DID (i.e. who the Decentralised Address Name Registrar has determined to be the owner) to access their ARD.
Decentralised Address Name Registrars may issue Verifiable Credentials as a service for address name spaces they manage, or for address name spaces managed by other entities (if they have a mechanism for verifying ownership).
An example of the latter might be verifying names issued as top-level/root domains by IANA as part of the current Domain Name System (DNS) used to resolve domains to network addresses (e.g. IP addresses). If a user wants to use an Address Name that matches a DNS name they have purchased (e.g. myname.com), Decentralised Address Name Registrars could provide a mechanism for verifying ownership of that domain name and then issue a Verifiable Credential confirming ownership. Like many traditional credentials, the Verifiable Credential issued can have an expiry date that matches the DNS domain's registered expiry.