Thanks for taking the time to look at our site so closely and ask about CSS validation.

There are two sets of CSS warnings/errors that show up for this site.

1) Properties that are only valid in non-Internet Explorer browsers, such as Firefox & Safari. Specifically, those properties do things like round the corners of the boxes that surround each tip and comment and change the opacity of the social-bookmarking icons below each post. In IE browsers those properties “degrade gracefully” – for example, by displaying as regular, sharp-edged rectangles, instead of rounded rectangles. Since these effects are entirely aesthetic we opted not to worry about the validation issue.

2) CSS declarations in the Yahoo User Interface (YUI) CSS reset code – http://developer.yahoo.com/yui/reset/ This code is widely used to reset CSS code on websites before custom code is applied. The reason some of it does not validate is that it uses asterisks to trick certain browsers – again, usually Internet Explorer, which has traditionally been resistant to standards-compliance – into behaving like standards-compliant browsers. In these cases, those workarounds trigger validation errors, but again, since they are intentional and do not have any ill effects, we leave them be.

I think the key thing with validation is to understand *why* each error is thrown and whether they have enough of an impact on usability, functionality, or display to live with them or not. 100% validation is ideal, but not always necessary.

I hope this answers your question – thanks again for dropping by!

I’m curious, though — your CSS throws up 32 errors at http://jigsaw.w3.org/css-validator/. (See sample results at http://jigsaw.w3.org/css-validator/validator?profile=css21&warning=0&uri=http%3A%2F%2Fwww.whenbadwebsiteshappentogoodpeople.com%2Ftip6%2F.) Is there a reason you don’t consider this to be a problem?

(I’m not being snide; I’m honestly wondering. I have never been certain how serious these sorts of errors are.)