It is as much hidden metadata as is any other of such attempts, like schema.org and what else exists. It is a not so beautiful repetition of stuff that is already in the html, true, but it stems from another way of thinking about metadata. Maybe the RDF community does not like it anymore, but it was a thing.
Note that I'm not fan of this, rel=trackback is what should be used. But it is not complicated to add those tags into a page, which was my point.
The DRY principle in its original form does not apply here: The information in those tags will change when the information in the database changes. They are not hardcoded.
Schema.org RDFa isn't hidden. JSON-LD in a script tag is but that's equivalently goofy.
"stems from another way of thinking about metadata"? Nope. It was a clumsy hack because they actually just wanted to put the <rdf:RDF> tags in the HTML but people would complain about HTML validation so they put it in a comment tag.
Comments
It is as much hidden metadata as is any other of such attempts, like schema.org and what else exists. It is a not so beautiful repetition of stuff that is already in the html, true, but it stems from another way of thinking about metadata. Maybe the RDF community does not like it anymore, but it was a thing.
Note that I'm not fan of this, rel=trackback is what should be used. But it is not complicated to add those tags into a page, which was my point.
The DRY principle in its original form does not apply here: The information in those tags will change when the information in the database changes. They are not hardcoded.
Schema.org RDFa isn't hidden. JSON-LD in a script tag is but that's equivalently goofy.
"stems from another way of thinking about metadata"? Nope. It was a clumsy hack because they actually just wanted to put the <rdf:RDF> tags in the HTML but people would complain about HTML validation so they put it in a comment tag.