How a comment on Hacker News led to 4½ new Unicode characters

If it knows about your new codepoint. Everyone using an implementation that doesn't yet support it is going to show the full URL. If history repeats itself, these implementations will be the majority for at least a decade.

> The question is implementation of what. I think that it is not an onerous requirement from applications that need to display emojis or ancient Egyptian hieroglyphs.

Except they need to do literally nothing different. Hieroglyphs are vectorized, and emojis are either bitmapped (which existing font formats already supported) or vectorized. None of this required a single line of code in any text shaping library to change. Text shaping libraries generally don't even need to understand Unicode categories or other metadata: font files already contain all the relevant information (directionality, combining mark, etc.).

> The use of italics in text may also carry crucial meaning. But if a textual representation as sup is supported, I don't see why the specialized rendering should be supported, too, but for math and not plain text.

If you scrub all bold and italics from text, do any of the words turn into different words? That's what happens with sup (or other named operators). Same thing for blackboard letters, fraktur, etc.

> I agree, but I think that that semantic information is preserved when writing N or NN instead of 𝑵 or ℕ. Considering that Unicode isn't enough to write most mathematical formulas convenient forms anyway and requires a specialized renderer anyway, I don't see the reason for this extra effort.

My point is it was better than nothing, which was the alternative when Unicode added these. By adding mathematical characters that worked exactly the same as all other characters, we could get some of the advantages of MathML without needing everybody to implement a special math renderer or learn any new markup, just download new font files.

If getting everyone to accept MathML or something similar in an expedited fashion was a reasonable proposition, then I might agree that they should've kept it out of Unicode. Those were not the facts on the ground when this decision was made. Note that even now that we have MathML, the few browsers that support it (IIRC Firefox & Safari only) have complete shit implementations that look terrible.

The crux of this is that making changes to a standard to support something new and propagating the changes is super hard; getting new standards to get accepted and implemented is a Herculean effort. Unicode's expansion into these domains required nobody to do anything differently, let alone decide to up and write an implementation of a completely different standard. I think this is a case were our alternative was to let the perfect be the enemy of the good, or at least the working.

And that's what happens when scrubbing subscripts or binomial coefficients. When you want to represent math as text, you need to change your representation (add multiplication signs, forgo subscripts, use confusing parentheses etc.). This is still true with Unicode. The contribution of the non-BMP special math characters is quite minimal.

> The crux of this is that making changes to a standard to support something new and propagating the changes is super hard; getting new standards to get accepted and implemented is a Herculean effort.

Sure, but the emoji craziness continues, and there's little sign it would ever stop. Instead of saying "this isn't text; if you want, call it 'special text', escape it, and let a different body standardize it", the body entrusted with standardizing text representation worries about how to represent a picture of two people kissing as text. What next? Kids would want to add tunes to their text messages. Would the Unicode Consortium add code points for MIDI? And maybe managers would want to standardize code points for organizational diagrams. Would that be the consortium’s responsibility, too? The BMP contains all the characters for reasonable text-art.

What is "plain text format" though? If 'text' isn't limited to Western ASCII characters (which it very obviously shouldn't be considering many people use other character sets), then the idea of a text standard should be to encode all the glyphs people use, so "plain text format" becomes a canonical list of all the communicative symbols in all languages. That's what Unicode aims to be.

In my opinion, if they're used for communication, it doesn't seem unreasonable that such a canon of characters should include universal iconographic symbols like the standby icon.