What's @ in OS X directory permissions?

Question

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ls -la symbolics… what does that last symbol mean?

Being unable to access my localhost via Parallels, I've found that the folder to which I was trying to access has permissions attributed drwxr-xr-x@ and so all of its files and subdirectories.

Mind the @ symbol. What does it mean?

I've also discovered that using mkdir creates permissions without the @ symbol. These directories ARE accessible to the VM. I generally suspect the @.

Your ideas?