frames and delivery units

One of my tasks is to look at the current HTML techniques and tests for
L3 SC4 and decide whether they belong to this success criterion. These
tests apply to frames.

Can someone who is more knowledgeable about HTML tell me whether frames
are separate delivery units, or part of the delivery unit for the page? 

If they are separate delivery units, these techniques should be moved to
GL 2.4 L2 SC4. If they are not separate delivery units, and we think
they should be covered by GL 3.1 L3 SC4, we need to reflect this is the
definition of "section".

Loretta Guarino Reid
lguarino@adobe.com
Adobe Systems, Acrobat Engineering