[taffronaut]

I miss the quaint DVB SI (ETSI EN 300 468) Content Descriptors with values that lumped together arbitrary categories (someone's subjective opinion) like: "serious music/classical music", or "popular culture/traditional arts". I thought they seemed strange in the context of a formal standard.

[tosti]

If it's opposites and multiple choice, you could drive a crude recommendation engine with that.