/* Absolute path */
body { background: url(/asserts/images/bg.png); }

/* Relative path */
body { background: url(../images/bg.png); }
body { background: url(../../asserts/images/bg.png); }

/* Delimiters */
body { background: url("/asserts/images/bg.png"); }
body { background: url(/asserts/images/bg.png); }
body { background: url( /asserts/images/bg.png    ); }
body { background: url('/asserts/images/bg.png'); background: url("/asserts/images/bg.png"); }

/* Escaped delimiters */
body { content: "<img src=\"/asserts/images/osi.svg\" />"; }

/* With query string and anchor */
body { background: url('/asserts/images/bg.png?a=b'); }
body { background: url('/asserts/images/bg.png#a'); }

/* Invalid */
body { background: url('bg.png'); }
body { background: url('/asserts/images/bg'); }
body { background: url('/asserts/images/bg.png.bak'); }
body { background: url('/asserts/images/bg.gif'); }
body { background: url('http://othersite.com/images/bg.png'); }