I doubt Dodd or Frank knew this fact. I also doubt that the genius team behind MIFIDII knew this fact....CATF/0123

What is FIX and what does it have to do with Fixed Income?

Simply put - FIX is a standard that allows fixed income trading systems to speak to each other. The FIX protocol language allows computers to exchange trade information using a series of message specifications. The FIX messaging standard is owned, maintained and developed through the collaborative efforts of FIX Trading Community™ member firms, which include many of the world’s leading financial institutions. 
FIX didn't always mean Financial Information eXchange protocol. It was originally called the Fidelity Information eXchange. Back in 1992, Fidelity introduced their electronic equity trading desk to the world. Robert "Bob" Lamoureux, Jacque Perold and Peter Lert of Fidelity developed a messaging protocol with the Chris Morstatt and James Leman of Salomon Brothers. This message protocol would allow computers on the equity desk of Fidelity and Salomon to TALK to each other. A radical concept in 1992 but not so much these days. The protocol was loosely specified so that it would be able to grow to become the the standard that it is today. FIX is quickly becoming the standard in most financial instruments for supporting all aspects of straight thru processing (STP) from pre-trade information to allocation information.