Schepers suggests that the term "WebID" is used for a class of solutions, not any one technology, but does not offer pointers nor discussion of any additional solution or technology to the information already present, which appear to me to be a singular solution and technology. I would like to see links to and information about the other members of this class, if such use does exist.
It is possible that Schepers is conflating WebIDs and the WebID Protocol (which uses but is not equivalent to WebIDs) ... which this page is evidently failing to clearly differentiate between. Contribution to that differentation would be helpful.
(This sort of conflation by overlapping name is nothing new to this area. I give you RDF, the data model, and RDF/XML, the XML serialization of RDF. Such conflation is troublesome, but not always avoidable.)