Just came across this at
www.IAEI.org (I know that some people had asked about it some time ago)
Relocatable power taps are intended to be directly connected to a permanently installed branch circuit receptacle. Relocatable power taps are not intended to be series connected (daisy chained) to other relocatable power taps or to extension cords. Relocatable power taps are not intended for use at construction sites and similar locations. Relocatable power taps are not intended to be permanently secured to building structures, tables, work benches or similar structures, nor are they intended to be used as a substitute for fixed wiring. The cords of relocatable power taps are not intended to be routed through walls, windows, ceilings, floors or other similar openings
It's in the "UL Corner" (a PDF file)
http://www.iaei.org/pdfs/02_B/02_b_ULQuestionCorner.pdf Bill
