Testing IE8.
/*/.test1 {background:#f88}/**/ - target IE8
head/*/+body/**/ .test2 - target IE8 (good for selector grouping)
html/*\*//*/* /**/ body .test5 - filter IE8 and maybe IE/Mac (seeing html * body)
html/*/* /**/ body .test6 - filter IE8 (seeing html * body)
*+html/*/* /**/ body .test7 - target IE7 and filter IE8
*+html/*/* /**/ .test8 - target IE7 and filter IE8
*+html/*/* /**/ .test8 - target IE7 and filter IE8
The last two hacks with a xml prolog or not to also target Opera 9.26 or ealier with the same hack.
More testing with X-UA-Compatible.
And more from Bruno Fassino - Essential css hacks.
And more from Alex Robinson - Basic tests for IE8 given various values of X-UA-Compatible.