CSS Diagnostics Script

/* Empty Elements */
div:empty, span:empty, li:empty, p:empty, td:empty, th:empty 
{ padding: 20px; border: 5px dotted yellow !important; }

/* Empty Attributes */
*[alt=""], *[title=""], *[class=""], *[id=""], a[href=""], a[href="#"] 
{ border: 5px solid yellow !important; }

/* Deprecated Elements */
applet, basefont, center, dir, font, isindex, menu, s, strike, u 
{ border: 5px dotted red !important; }

/* Deprecated Attributes */
*[background], *[bgcolor], *[clear], *[color], *[compact], *[noshade], *[nowrap], *[size], *[start], 
*[bottommargin], *[leftmargin], *[rightmargin], *[topmargin], *[marginheight], *[marginwidth], *[alink], *[link], *[text], *[vlink],
*[align], *[valign],
*[hspace], *[vspace],
*[height], *[width],
ul[type], ol[type], li[type]
{ border: 5px solid red !important; }

/* Proposed Deprecated Elements */
input[type="button"], big, tt 
{ border: 5px dotted #33FF00 !important; }

/* Proposed Deprecated Attributes */
*[border], a[target], table[cellpadding], table[cellspacing], *[name] 
{ border: 5px solid #33FF00 !important; }

Source