I believe they are much more legitimate symbols to put to Unicode than Emoji. They are standardized (IEEE 1621), they frequently appear in the running text (of

I believe they are much more legitimate symbols to put to Unicode than Emoji. They are standardized (IEEE 1621), they frequently appear in the running text (of particular kind, but widespread enough), and they have distinct semantics from existing characters and symbols. In terms of worthiness they are on par with math symbols, enough for justifying the inclusion.