On Tuesday 2010-07-13 09:57 +0100, Philip Taylor (Webmaster, Ret'd) wrote: > Is there, therefore, in CSS, some way of specifying as a part of the > font fallback sequence that any font selected as a result of fallback > must support a specific subset of Unicode such that the page can be > guaranteed to display correctly provided that such a font does in > fact exist on the visitor's machine ?
As was already pointed out, this is already guaranteed by CSS. I'd like to explain in a drop more detail, though: Font fallback is defined by CSS as being *per character*. In other words, for each character, the implementation is required to find the font that best matches the font-family, font-weight, font-style, etc. This is defined in CSS 2.1: http://www.w3.org/TR/CSS21/fonts.html#algorithm see especially bullet (2) ("and for each character in that element"), bullet (4) ("but it does not contain a glyph for the current character"), and bullet (5) ("If a particular character ..."). So the list given in the font-family property is a list of fonts to be searched for each character in the text that is displayed, and the generic families (explicitly or implicitly at the end of that list) should cover a large set of fonts. Browsers should not display a "missing glyph" symbol unless there's no font they can access with an appropriate glyph. I suspect that browsers don't actually follow this algorithm to the letter (it's rather hard to test, for a start). However, I think major browsers are generally quite good about finding some usable font, if present, before falling back to a missing glyph symbol. -David -- L. David Baron http://dbaron.org/ Mozilla Corporation http://www.mozilla.com/ ______________________________________________________________________ css-discuss [cs...@lists.css-discuss.org] http://www.css-discuss.org/mailman/listinfo/css-d List wiki/FAQ -- http://css-discuss.incutio.com/ List policies -- http://css-discuss.org/policies.html Supported by evolt.org -- http://www.evolt.org/help_support_evolt/
