Specific use case is for “claiming” pages. Standard Site does this kind of indirectly, but I should be able to put my DID in a page, and then in a system like Semble, “claim” that URL, and Semble could verify that. Very hand wavy description and I’m not set on this.
As well, at:[something] follows a vendored set of attributes like og:
Aram pushed us previously towards Schema.org, but regardless this conversation may be useful: