Re: [External] Pop Quiz: Where do DIDs belong from an Enterprise Architecture perspective?

DIDs are points of control. We talk about "DID controllers". If a user has points of control but doesn't know she has them, in what sense(s) is she really in control? Pet names make points of control tractable from a human memory perspective, but if the mental model of a user doesn't have a place for the control point that they name, do we truly understand what we are accomplishing? Do we need to? How does this relate to sovereignty?
E-mail address is a point of control. As a user, you can share your address daniel.hardman@gmail.com with me without knowing that the MX records of gmail.com point to 142.251.167.26 (and other IP addresses).
 Web domain is a point of control. Many people can host content on their web site and publish the URL addresses of their pages without knowing the IP address the server is hosted on.
DNS provides a public mapping between (human readable) domain names and IP addresses. Since DID addresses may be even more complex and hard to grasp than IP addresses, there might be a need for a DNS-like system for DIDs.
We might get away with pet names - a system where I store your DID giving it an alias “Dan H” in my address book. However, pet names don’t work so well when we bring third parties and non-digital communication into the picture.
To answer Michael’s original question about the domain of DIDs, a DID is a (technical) attribute of an entity that usually belongs to the Business domain. (Applications and hardware devices might have DIDs, too.) Taking an attribute (especially an identifying attribute) from an entity and moving it to another domain easily leads to more confusion than clarity.
Of course, you might create models where persons are in the Business domain, their e-mail applications (including e-mail addresses) are in the Application domain and the servers running those applications (identified by IP addresses) are in the Technology domain. This model kind of works for gmail addresses etc. (your gmail address only identifies your email “application" provided by Google) but is quite misleading if you consider e-mail addresses you really own yourself and can point to any provider. It would be better to model the email address as an attribute of a person.
A hostname can be used to identify an organization. (There are other uses, too.) Since DNS provides a mapping between IP addresses and hostnames, and this mapping can change, it is reasonable to model the hostname as an identifier of an organization and the IP address as an identifier of a server hosting the organization’s website (or mail servers etc.).
If we had a DNS-like system providing a mapping between DIDs and their human-readable counterparts, we might model the human-readables as the attributes of actors and DIDs as attributes of technology (like IP addresses). But since we don’t have that mapping and the purpose of DIDs is not to identify servers (like IP addresses), I claim that DIDs belong to the domain where the objects they identify belong to. Personal and organizational DIDs belong to the Business domain. If there is a DID for an application, that DID belongs to the Application domain.
All models are wrong, but some are useful.
      Samuel