Css with selector #id1#id2 set styles for node with id "id2"
How it works in html css :
http://www.w3.org/Style/CSS/Test/CSS3/Selectors/current/html/static/flat/css3-modsel-15b.html
How it works in html css :
http://www.w3.org/Style/CSS/Test/CSS3/Selectors/current/html/static/flat/css3-modsel-15b.html