Effective Sunday, December 4, 2005 (for trade date Monday, December 5, 2005), CME® will begin disseminating bids/asks on spread data with a bid/ask size that exceeds 99,999 via a new ITC 2.1 message, Category Code “b” (currently sent as a Category Code “B”).  The Chicago Board of Trade already uses message type “b”, so distributors may already be familiar with it.  For your convenience, a copy of the “b” message type layout is attached.