This file demonstrates a <frame> that contains an invalid "src".
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> <html lang="en"> <head> <title>aert1.0/6.2.1</title> </head> <frameset> <frame src="rex.jpg"> </frameset> <body> </body> </html>