On Tue, Jun 16, 2015 at 1:51 PM, Edward O'Connor <eocon...@apple.com> wrote: > Hi Elliott, > > You wrote: >> I'm fine with either interpretation, mask-icon or "icon mask" like >> "alternate stylesheet". I don't think adding a mask attribute to the >> HTMLLinkElement for this makes sense. > > Could you elaborate? It's not clear to me why <link rel=icon mask> > wouldn't make sense, but <link rel=icon sizes> does. They are both > useful advisory hints that help UAs avoid redundant resource loads.
"sizes" really is an advisory hint; if you don't understand it and just download one of the icons, at worst you'll get a version that needs to be scaled up or down. Accidentally displaying a "mask" version of the favicon can give substantially worse results; the design tradeoffs made for mask icons can be substantially different than those for favicons, and result in a completely unsuitable icon (particularly if rendered in solid black, as is currently recommended). Note the WHATWG thread from two days ago about <link rel=icon mask> already being seen in the wild and having precisely this problem, where the simplest conclusion appears to be *specifically ignoring the mask links*. <https://lists.w3.org/Archives/Public/public-whatwg-archive/2015Jun/0011.html> ~TJ