That’s an incredibly interesting document. Really fun thinking.

This document defines two URI schemes. The first, ‘duri’ (standing
for “dated URI”), identifies a resource as of a particular time.
This allows explicit reference to the “time of retrieval”, similar to
the way in which bibliographic references containing URIs are often

The second scheme, ‘tdb’ ( standing for “Thing Described By”),
provides a way of minting URIs for anything that can be described, by
the means of identifying a description as of a particular time.
These schemes were posited as “thought experiments”, and therefore
this document is designated as Experimental.