The Media Fragments Working Group has published the First Public Working Draft of Use cases and requirements for Media Fragments. The aim of this specification is to enhance the Web infrastructure for supporting the addressing and retrieval of subparts of time-based Web resources. Example uses are the sharing of such fragment URIs with friends via email, the automated creation of such fragment URIs in a search engine interface, or the annotation of media fragments with RDF. This specification will help make video a first-class citizen of the World Wide Web. In addition to describing use cases for the Media Fragments 1.0 specification, this document discusses syntax and processing of media fragment URIs, and offers survey of technologies that address multimedia fragments. Learn more about the Video in the Web Activity.
A lot of use cases including on about adapting media resources but some are marked out-of-scope. Why are they still there? Furthermore, "just four requirements" related to temporal, spatial, track, and named fragments have been defined. There's an overlap between named fragments and the rest and it seems they're more seeking for human readability and named fragments is the solution for that requirement. Just take this as a remark.