Double right arrowhead?

[Asmus Freytag]

Symbols are distinct from letters in that the latter have a strong 
customary identity that maps onto a sometimes surprising range of font 
designs. The functional requirement for a glyph for a letter is that it 
is recognizable in context so that the underlying letter can be 
identified. Users of Fraktur fonts have no problem with a glyph for A 
that in isolation might be mistaken for a U by readers not familiar with 
that style.

Even then, not all fonts are usable for all purposes. There are Latin 
fonts that drop the dot on the 'i'. Those can't be used for Turkish, 
where the dotted and dotless 'i' are distinct. However, they work fine 
for English, and they are not that rare. Readers who are not used to 
looking for typographical design quirks might not even notice.

For symbols, there is usually a lot less context; they don't form part 
of words, for example. And the shapes are often very simple or 
geometric. Take a simple triangle, pointing right. Is a black (filled) 
one a different symbol from a white (open) one? Is an short, tall 
triangle shape a different symbol from a long wide one?

Generally, we say yes, so symbols have a much narrower range of 
acceptable (expected) glyph shapes.

Punctuation are somewhere in between. Whether a period is square or 
round doesn't matter in the context of running text. Both are equally 
acceptable so we typically leave that to the font. At the same time, the 
character is reused for any dot on the baseline, whether period or 
decimal point.

Common to symbols and punctuation is that they can be mapped onto more 
than one concept; this is easier if the range of acceptable glyphs is 
narrower. This supports the suggestion made here to look for the 
intended shape, and if an existing symbol is a good or perhaps even 
precise match, then the suggestion would be to perhaps recognize that 
alternate use in an annotation (if that use is considered common and you 
want to guide users in making a consistent selection).

Yes, it's useful to look at a couple of the most common fonts to make 
sure that the actually deployed range of glyphs matches the new usage. 
In case where some symbol unexpectedly shows an interesting variation of 
appearance, adding another use to it might not work. In particular, if 
these are not outliers, but common alternations. But unless that 
research has been done and there's conclusive evidence that adopting an 
existing symbol for that use case is unworkable, there's not even enough 
basis for discussing a new character proposal.

That said, I'm not in favor of adopting an existing character if the 
expected glyph for it is only a rough approximation of a preferred 
shape. I totally get that not all arrowheads look the same, and that 
there is room therefore, for a variety of them in the standard. However, 
any proposal claiming that every single existing one is insufficient has 
the burden of demonstrating that.

A./


On 7/27/2025 10:56 AM, Doug Ewell via Unicode wrote:
> Alex Plantema wrote:
>
>> Characters may look useful in one font, but not in other fonts. Are
>> you going to check them in all fonts?
> A character may have somewhat different appearances in different fonts, as long as the basic identity of the character is preserved. That’s what characters are:
> https://www.unicode.org/reports/tr17/#CharactersVsGlyphs
>
> Even emoji don’t look exactly the same in every font. Even characters in the Dingbats block don't.
>
> If you require such a specific appearance for this symbol that "check them in all fonts" is considered necessary, then you are not looking for a character; you are looking for a glyph, and for that an inline image is probably the best choice.
>
> --
> Doug Ewell, CC, ALB | Lakewood, CO, US | ewellic.org
>
>