wtkad - 12:46 pm on Aug 7, 2007 (gmt 0)

I currently use the base element because I need the same code to work in three different places:
My computer (127.0.0.1/example/)
The test site (www.anotherdomain.com/folder/example/)
The actual site (www.example.com)
It's much easier to change the base tag for each location than to change all the links and includes every time it's moved.

But I do get 404 errors like:
www.example.com/folder/stylesheet.css
Even though the base tag should make it:
www.example.com/stylesheet.css
I don't know what user-agents those come from, and I've never seen a wrong one in Google Webmaster Tools, but it does happen. It could just be the smaller bots that no one wants anyway. But it verifies the above caution - if you're relying on being spidered perfectly, you probably shouldn't depend on the base tag.

On the next redesign, I'm planning to use a different system for code transporting myself.