From MozillaZine Knowledge Base
HTML frames allow web designers to display multiple documents in one tab. Normally, the space taken by each document can be changed by the user by dragging the separator. Web designers can specify the noresize attribute on their frames to prevent resizing. This preference determines whether the noresize attribute will be overridden.
Possible values and their effects
HTML frames are always resizable.
HTML frames are resizable, except if the noresize attribute is present. (Default)
First checked in
Has an effect in