17 CFR 1.72: Restrictions on customer clearing arrangements.

No futures commission merchant providing clearing services to customers shall enter into an arrangement that:

(a) Discloses to the futures commission merchant or any swap dealer or major swap participant the identity of a customer's original executing counterparty;

(b) Limits the number of counterparties with whom a customer may enter into a trade;

(c) Restricts the size of the position a customer may take with any individual counterparty, apart from an overall limit for all positions held by the customer at the futures commission merchant;

(d) Impairs a customer's access to execution of a trade on terms that have a reasonable relationship to the best terms available; or

(e) Prevents compliance with the timeframes set forth in § 1.74(b), § 23.610(b), or § 39.12(b)(7) of this chapter.