Noah Melnik is a lawyer with LinkLaters who runs a useful blog (here) which you should follow. He has posted via LinkedIn a PDF for LinkLater's clients on how extra-territoriality works, along with the rules for registering as a Swap Dealer (SD) or Major Swap Participant (MSP). The note is important for any firm outside the US, especially those with a hub and spoke risk booking structure, who may need to understand how the CFTC rules reach out beyond the borders of the US. Here is the PDF.