Allow or disallow URLs from local root.
"always"
, "never"
/* Okay: */
background: url(/foo/bar);
background-image: url('/foo/bar');
content: url("/foo/bar");
/* Error: */
background: url(foo/bar);
background-image: url('foo/bar');
content: url("foo/bar");
/* Okay: */
background: url(foo/bar);
background-image: url('foo/bar');
content: url("foo/bar");
/* Never: */
background: url(/foo/bar);
background-image: url('/foo/bar');
content: url("/foo/bar");