Re: Too narrowly defined: DIVISION SIGN & COLON

From: Philippe Verdy <>
Date: Wed, 11 Jul 2012 03:39:23 +0200

I was looking in my fonts and did not see the three dots. Thanks for
pointing the font that my browser seems to use to render it this way.

(Unfortunately it's still almost impossible to determine how browsers
are selecting fonts and which fonts get finally used to render text in
their tricky code, because these bindings and fallbacks are completely
unacessible via the DOM in their debug interface, which just shows the
computed list of font-families and other font properties, but not the
actual fonts that will be selected from these CSS properties (there
are additional fallback mechanisms, some impelmtned in the browser
itself, some as part of their layout engine, if it's not using the OS
support dor the layout, some other as part of font formats such as
font collections and virtual fonts, some as parts of specific font
drivers installed on the system, and some as part of the core OS
itself notably in Windows), plus some fonts that are emulated
internally in the browser or renderer, without using any visibly
installed fonts (notably spaces, and simple geometric shapes like
dots, hyphens, squares).

Now on a system where there are hundreds of fonts installed. Searching
for it is really a nightmare (I would hope that some charmap tool
would allow enumerating simply which fonts are mapping some
characters, and comparing the glyphs or navigating in the list of
fonts to see rapidly how each one behaves. But even in that case, the
text renderers used in the charmap tool could produce results distinct
from those produced by the browser which may use other fallback

Is that 3-points presentation of the ratio character in Lucida Sans
justified in some contexts ? Or is is a way for it to force a visible
distinction (just like we have some fonts or renderers that display a
distinctive symbol, possibly half -transparent or grayed, for space
characters, in edit modes). It looks strange to me because there's no
edit mode enabled in my browser when just viewing an email, and Lucida
Sans is not very well suited for such edit modes (it lacks many
distinctive glyphs). It may be an accident left in the font design
(incorrect mapping, missing or incorrectly interpreted conditional
OpenType feature, or something forgotten in the assigned glyph where
the additional dot mark was meant for "work to be done later here"...)

2012/7/11 Mark Davis ☕ <>:
> I am using the ratio character in the final 3∶5. Whether or not there is a
> distinction between that and 3:5, and what that distinction is, seems to
> depend entirely on the font in question.
> Bizarrely, it does seem to have 3 dots in Lucida Sans.
> ________________________________
> Mark
> — Il meglio è l’inimico del bene —
> On Tue, Jul 10, 2012 at 5:07 PM, Philippe Verdy <> wrote:
>> 2012/7/11 Mark Davis ☕ <>:
>> > I would disagree about the preference for ratio; I think it is a
>> > historical
>> > accident in Unicode.
>> >
>> > What people use and have used for ratio is simply a colon. One writes
>> > 3:5,
>> > and I doubt that there was a well-established visual difference that
>> > demanded a separate code for it, so someone would need to write 3∶5
>> > instead.
>> Is that me or I see 3 vertical dots in your last line (instead of 2
>> vertical dots for the usual colon) ? This unusual sign is certainly
>> NOT the one used to note scales on maps or ratios. We use and see the
>> 2-dots colon almost always.
>> The 3-dots symbol (or punctuation) is clearly distinct, and not an
>> accident. It is very uncommon. It is not a duplicate encoding. May be
>> it is used for noting ratios (I've never seen that) or as
>> asupplementtary mathematical operator, or as a custom separator
>> similar in use to the vertical pipe in some contexts that require
>> several types of separators visually distinct.
>> Did you type the correct character ?
Received on Tue Jul 10 2012 - 20:40:41 CDT

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