I mentioned this at the language summit in Pune, we'll need to add in extra controls to allow for some languages to have more fine grain control of the leading, font size micro-adjustments and in some cases letter spacing of non-latin alphabets. We want to have the same overall weight and texture of paragraphs irrespective of the characters being used. For that to work we'll need to do some one off adjustments for alphabets that are more optically dense or use a lot of diacritic marks that go well above or below baselines. 

Is there a bug logged for this?

Jared Zimmerman  \\  Director of User Experience \\ Wikimedia Foundation               
M : +1 415 609 4043 |   :  @JaredZimmerman

On Mon, Dec 2, 2013 at 4:29 AM, Amir E. Aharoni <amir.aharoni@mail.huji.ac.il> wrote:

2013/12/2 Nick White <nick.white@durham.ac.uk>
On Sat, Nov 30, 2013 at 01:51:39PM +0200, Amir E. Aharoni wrote:
> That is, more or less, the reason why W3C recommends using <em> rather than
> <i>. Ideally the ''double apostrophe'' in wiki-syntax will insert <em> (now it
> inserts <i>), and we'll have styling somewhere along these lines:
> .script-latn em {
>     font-style: italic;
> }
> .script-hebr em {
>     font-weight: bold;
> }
> (Of course, this is just a simplistic suggestion and the actual styling may be
> different.)

I know this was just an illustrative example, but I'm curious
whether there's any reason not to use the :lang css construct for
cases like this (rather than e.g. .script-hebr)?

So you'd set <body lang="hebr">, then use rules like:
:lang(hebr) em {
    font-weight: bold;

I'm just checking that there's no good reason not to use this,
because that's what I've been doing with an extension I wrote[0] ;)

"hebr" is a four-letter ISO 15924 writing system code. Such things are more oriented to writing systems than to languages. There is no standard HTML attribute for a writing system. If all the languages that use the Hebrew script have the same design it is easier to group them this way. That's what Bug 57045 is about.

Of course, it's quite possible that some particular languages would have special properties, and for them it's possible to use :lang(he) as you propose, but with a two- or three-letter language code according to the ISO 639-3 language code.
0. https://www.mediawiki.org/wiki/Extension:CharRangeSpan

Curious, I'll take a look. Thanks for the link.

Amir Elisha Aharoni · אָמִיר אֱלִישָׁע אַהֲרוֹנִי
‪“We're living in pieces,
I want to live in peace.” – T. Moore‬

Design mailing list