Related to my message about adding a snapshot's provenance metadata to an html page: besides the provenance of the document as a whole, I would also like to keep available the original URLs in places where they have been rewitten; something that may be interesting more generally for archives that rewrite links.
The robust links spec seems to provide a nice way to add such metadata, by adding the data-orginalurl and data-versiondate attribute to an <a> tag (by the way, do any archives use this?). This seems close to what I am looking for, except that I would also like to use it for other types of tags and attributes than just the <a>'s href. For example, in freeze-dry, when an image is inlined as a data URL (<img src="data:image/png;base64,PD94bWwgdmVyc2....">), the original location is currently put in a data-original-src attribute. Note that simply adopting data-originalurl seems inadequate here, as perhaps we also want to add the original value of the srcset attribute.
I thought there might be some interest in generalising the robust
links spec, or creating a separate spec, to cover any links in any
element attributes (or maybe also non-link values of attributes).
I'd be happy to hear if anyone has thoughts about this.
Gerben