data URIs being regarded as invalid

Ian Yang <[email protected]> Sat, 1 Jun 2013 00:13:46 +0800
Newsgroups gmane.org.w3c.validator.css
Message-ID <CAFhBhuMwsufsc8UXNdBoiLsU4f8MBNj0m=1DN=rAVOYLR+gxsQ@mail.gmail.com>
data URIs being regarded as invalid.

Pleasee see here for details:
http://stackoverflow.com/questions/15481088/are-unquoted-data-uris-valid-in-css