Re: Contrast specification in Style Sheets

Scott E. Preece (
Tue, 12 Sep 1995 17:12:05 -0500

From: "Terry Allen" <>
| Thanks for the good example, Evan. I think this is part of a bigger
| problem (other parts of which include generated text that must
| be displayed, prohibitions on hiding certain elements, and legally
| required display characteristics of e.g. safety warnings), to which the
| only solution I can see is that authors must be able to specify
| that their style sheet be used or the document not be displayed.

I think this particular nail (specifying that certain presentations must be distinct) doesn't require that hammer. There are two parts to the problem - one is representing that the distinction needs to be made, the other is representing whether the distinction is mandatory (can't display if not satisfied) or not. The latter is the problem you cite, the former is the one Evan raises. They're both required, but Evan's does require some kind of notational support in the stylesheet.

A couple more ways to represent this might include:

EM.class1 : font-weight != EM.class2 : font-weight


EM.class1, EM.class2 : font-weight = distinct


scott preece
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