Do values in CSS attribute selector values need to be quoted?

Question

e.g.:

a[href=\"val\"]

Does \"val\" need to have quotes around it? Single or double are acceptable? What about for integers?

Answer 1

According to the examples in the CSS 2.1 specs, quotes are optional.

In the following example, the selector matches all SPAN elements whose "class" attribute has exactly the value "example":

span[class=example] { color: blue; }

Here, the selector matches all SPAN elements whose "hello" attribute has exactly the value "Cleveland" and whose "goodbye" attribute has exactly the value "Columbus":

span[hello="Cleveland"][goodbye="Columbus"] { color: blue; }

Numbers are treated like strings, i.e. they can be quoted, but they don't have to.