Just to confuse things even more, remember that you can have multiple classes:
<div class="regular @lang@" >Some stuff</div>
Here is a quick example of using icons from a stylesheet, and alt text for non graphical browsers:
http://junom.com/document/
This is just a massaged dir_proc from AOLserver used with the tigris.org stylesheet.
Stylesheet composition is very tricky and depends entirely on order in some cases, and also upon errors. Debugging an issue is also very difficult because you may never get access to the users' setup. It is kind of like javascript, without the error messages to help you out.
The regularizing of forms and other reused blocks of markup will help the most for anyone trying to re-style a site, so one idea for variations at a package level would be to use div at some level which acts like a breadcrumb trail:
class="myclass site1 forums forum1"
If the default 'myclass' is all that exists, you get the default behavior. If someone adds site1 styles, these get mixed in (don't ask me how), etc. You don't have to do this at every point, just at reasonable levels, maybe only one per page, or at package boundaries.
