h5bp/html5-boilerplate — comment on commit aa0396eae757c9e03dda4e463fb0d4db5a5f82d7
File:  line 0
By jcutrell:

http://www.w3schools.com/browsers/browsers_explorer.asp
1% (other sources cite 2-3% as well) seems like a low enough margin to begin accepting less-than-ideal ie6 solutions that improve performance for the higher-margin bases (Chrome 16 and 17 together hold ~32.4%). I'd say Firefox 3.6 is the browser to really worry about (fortunately not in this case, though.)

I don't think there's anything wrong with writing "shiny" code as long as it's valid or all browsers work with it. There's a good reason why "0/0 a" is used here; it is the shortest version of code, and if it becomes a standard, people will recognize it for what it does, not what it semantically means.

IE6 users shouldn't be ignored, true; however, there is a hierarchy of importance in these decisions.