I incline to "Yes", with laitaine's method of choosing colours, but rho's alternative solution might be better. I think people using visual browsers and mice expect to see highlight-to-read spoiler text because that's what you get elsewhere, and it's pretty easy to code ... if you don't care about accessibility. I've got a bookmark to the cheat-sheet for an accessible method, and it's really complicated. A pseudo-html tag would take away a lot of effort in applying the cheat-sheet, and could be updated if new methods became available, but it would still be some clumsy-looking code. An extra parameter on a cut-tag to make it stay closed unless specifically opened would be spiffy.
no subject