metadata is an opinion
Kiran's opinion that I appropriated. The idea is that there is no such thing as canonical metadata, because there is no such thing as an ultimate ontology. Related to the problem of the copula.
This comes up, for example, in the context of digital archives. A digital asset often comes packaged with metadata, which is attached to it with better or worse "adhesive" so to speak: sometimes as an nfo zipped or tarred into the same archive, sometimes in the frontmatter of an mp3 or mkv, sometimes distributed with filenames that help you line up related assets and note them as related. And of course as all of these are channels of communication, all of them are written, overwritten, passed on, or deleted as every link in the transmission chain sees fit. What then are you choosing to archive? The artifact available to any archive is an eccident of fate, data irrevoably entangled with the place in the state machine that its was observed, the site of the archive collector. (This entanglement reminds me of the Open Memetics Institute, weather balloons, and pointed models.)