Re: Why no combining‐character form for U+00F8?

From: Asmus Freytag <>
Date: Thu, 16 Aug 2012 09:21:43 -0700

On 8/16/2012 8:31 AM, Ian Clifton wrote:
> Having just been to Norway, and wanting to email my friends all about
> it, I came across a curiosity: neither of the combining characters
> U+0337, U+0338 seem to work in usually‐reliable Emacs, and indeed
> U+00F8 LATIN SMALL LETTER O WITH STROKE doesn’t seem to have a
> decomposed form, according to UnicodeData.txt. I’m sure this can’t be an
> oversight?
I believe the principle is something like this: if a mark overlays the
character, like a stroke, it's not considered composable. One factor in
this is that diagonal strokes are far less likely to occur on a wide
range of characters - compare it to the various accent marks, some of
which might be applied to characters of many scripts even, for the
purpose of marking stress etc. independent of a particular orthography.

Typographically, they are also a bit more challenging, because simply
locating a generic stroke glyph, even with anchor points would not give
you good results, many, pehaps most combinations would require a
specific length and inclination for the stroke as well. At that point,
typographically, you'd be just as well off not bothering about combinations.

I think it was a mix of those considerations that lead to an early
design decision not to decompose these.

Because (outside mathematics) such strokes are not used in ways that
produce novel combinations, the effect of this "inconsistency" is minor,
so it is unlikely that any more rigorous decomposition would have
noticeably "improved" the standard - other than your attempt at
composing these.

For stability reasons, that decision is now frozen, so even if
discussion were to prove that an alternate strategy would be marginally
"better", nothing could change anyway.


Received on Thu Aug 16 2012 - 11:25:20 CDT

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