In response to a collective recommendation (at Perth Hackfest) that HTML markup, IDs and classnames should be simplified or standardized in order to make theme development faster and more foolproof, I've surveyed activity types and recorded some recommendations here: http://docs.moodle.org/dev/Standardize_classnames_and_layout_to_facilitate_theming

I will create the recommendations as children of this task. Many of these child tasks would require significant time looking into the renderers and markup in order to even determine scope. I will capture them here to the best of my ability and hope that the community contributes with comments, ideas, and hopefully code.

Generally, these tasks are meant to address things in core that theme designers don't have access to using the layout files.