frameborder ist ein http://de.selfhtml.org/html/allgemein/textauszeichnung.htm#attribute@title=Attribut (was nicht zum HTML-Standard gehört).
http://www.w3.org/TR/html4/present/frames.html#adef-frameborder
frameborder = 1|0 [CN]
This attribute provides the user agent with information about the frame border. Possible values:
1: This value tells the user agent to draw a separator between this frame and every adjoining frame. This is the default value.
0: This value tells the user agent not to draw a separator between this frame and every adjoining frame. Note that separators may be drawn next to this frame nonetheless if specified by other frames.