Thanks! I thought for a moment that we could add "jsonld" for pointing to a document containing that data. But that seems not to be the intention of the nip.
Discussion
Yes, you could. But JSON-LD is getting full of confused compromises because it wasnt backwards compatible with JSON. IMHO a mistake. I spent quite some time trying to fix it once and for all, but it's ended up as various different incmpatible hacks. We can do better, simply by adding a vocab property @vocab : urn:json: which will convert all json to json-ld.
curl -LH'Accept: application/ld+json' https://w3c.social/@csarven
will give you activity pub with a context that can be interpreted as a form of json-ld I am told.
But ask @csarven@w3c.social
The #ActivityStreams core standard
https://www.w3.org/TR/activitystreams-core/#jsonld
says
“The serialized #JSON form of an Activity Streams 2.0 document must be consistent with what would be produced by the standard #JSON-LD 1.0 Processing Algorithms and API [JSON-LD-API] Compaction Algorithm using, at least, the normative JSON-LD @context definition provided here.”
So that means that Activity Streams should have a good extensionality story, and so adding tags with semantic content should not be too difficult.
Re tags. There was a company called Faviki that did a very good job of linking #tags to Wikipedia, via DBpedia, perhaps. This allowed people to come to agreements over tags in a communal way, and it allowed one to search for similar tags or implied tags. (also it could help with translation between tags)
I wrote about Faviki somewhere on blogs.sun.com, but I did not find it. Here is one thing I wrote on the subject:
Sorry I meant to link to the web archive version of the blogs.sun.com post https://web.archive.org/web/20091004034050/http://blogs.sun.com/bblfish/entry/search_tagging_and_wikis