Beginning December 21st, 2013, all FCMs, certain IBs, and RFEDs must begin to tape record all oral communications provided and/or received in regard to quotes, bids, offers, solicitations, trading, instructions, trading and prices that lead to execution of these transactions.

This includes a wide range of oral communications including telephone, voice mail, mobile phone, or other digital and electronic media.  All recordings must be kept for one year.  The detail of the amendment to CFTC Regulation 1.35(a) can be found on Page 2 here.