.a {
	background: url(./img.png);
	background: url("./img.png");
	background: url("./img img.png");
	background: url('./img img.png');
	background: url('./img.png');
	background: url("./img.png#?iefix");
	background: url("#hash");
	background: url("#");
	background: url(data:image/png;base64,AAA);
	background: url(http://example.com/image.jpg);
	background: url(//example.com/image.png);
	background: green url(data:image/png;base64,AAA) url(http://example.com/image.jpg) url(//example.com/image.png) url(./img.png) url('./img img.png') xyz;
}