Re: [css-fonts] "system" generic font name

It might be worth having a slightly longer privacy discussion about this and similar features, but a quick question for now.

Is "system" intended to select the default font-family used by that version of the operating system, or a potentially user-selected font to match the font currently used on that machine for menus and OS-provided controls? The "menu" value as defined in CSS3 Fonts is a little vague on that point.

To the extent that "system", "menu" or "-headline1"-type properties reflect user-selected preferences, this could expose increased browser fingerprinting surface or reveal something about the user's vision (e.g. this user has increased their font size and may have reduced vision).

To the extent that these aren't user preferences but just make it trivially easy for sites to render more Mac-like on Mac machines and Android-like on Android devices, awesome.

Thanks,
Nick
> > On 15 Jul 2015, at 8:47 AM, Robert O'Callahan <robert@ocallahan.org <mailto:robert@ocallahan.org?Subject=Re%3A%20%5Bcss-fonts%5D%20%22system%22%20generic%20font%20name&In-Reply-To=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E&References=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E>> wrote:
> >
> > On Wed, Jul 15, 2015 at 10:24 AM, Dean Jackson <dino@apple.com <mailto:dino@apple.com?Subject=Re%3A%20%5Bcss-fonts%5D%20%22system%22%20generic%20font%20name&In-Reply-To=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E&References=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E> <mailto:dino@apple.com <mailto:dino@apple.com?Subject=Re%3A%20%5Bcss-fonts%5D%20%22system%22%20generic%20font%20name&In-Reply-To=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E&References=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E>>> wrote:
> > > On 15 Jul 2015, at 7:42 AM, Felix Miata <mrmazda@earthlink.net <mailto:mrmazda@earthlink.net?Subject=Re%3A%20%5Bcss-fonts%5D%20%22system%22%20generic%20font%20name&In-Reply-To=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E&References=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E> <mailto:mrmazda@earthlink.net <mailto:mrmazda@earthlink.net?Subject=Re%3A%20%5Bcss-fonts%5D%20%22system%22%20generic%20font%20name&In-Reply-To=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E&References=%3CF93367A8-E25E-49DF-ADB3-05F849861519%40apple.com%3E>>> wrote:
> > >
> > > Wouldn't your "system" be equivalent to or duplicative of one or more of the
> > > 6 existing "system" fonts on http://www.w3.org/TR/css3-fonts/#font-prop <http://www.w3.org/TR/css3-fonts/#font-prop> <http://www.w3.org/TR/css3-fonts/#font-prop <http://www.w3.org/TR/css3-fonts/#font-prop>> ,
> > > e.g. menu?
> >
> > This whole thing is weird. It makes specifying fallback font-families strange - you now move them to the font shorthand.
> > Even though you can then override size/weight/etc after the shorthand, it seems yucky that you have to use a shorthand just to get what is effectively a font-family.
> >
> > Per David's email, don't you also need a way to set font size/weight etc to values that match system usage? And isn't the 'font' property the best way to do this?
> 
> Not at this point. Or, more accurately, not with this proposal. We just want to match the family.
> 
> Aside: on iOS we do have similar font keywords like your -mozilla-foo. For example, -apple-system-headline1, which provides a family, weight, style, size, etc. These also dynamically respond to what the user chooses in their accessibility settings. We're not talking about those in this proposal.