The CME informed me that "7C7" translates to 737. 737 is the number for the firm named Advantage. The counter party number "7C7LCME737" identifies all advantage customers (proprietary and non member). The "L" represents a method of access. Counter party acronyms that begin with three alphabetic letters are from individuals that own their own individual membership. CME acronyms that end in three numbers followed by a letter are subgroups of a clearing firm. 1B5LCME125 is a Fortis number. TMG has it's trades processed through Fortis, so this number is an identifier for TMG and any other Fortis customer that goes through Fortis. Thus TMG cannot identify trades as TMG trades by looking at this acronym. The good thing is that no one else can identify a Trade as originating from TMG from this acronym. For the most part, I find Counterparty information to be useless. I will investigate this further and report back soon. In the mean time is anyone has additional information or if some of what I have written is in error, please reply. Ray