Package FIX 5.0 SP2 Volume 1 Specification with 20110818 Errata Volume 1 of the FIX 5.0 Service Pack 2 (with 20110818 Errata) contains the FIX tag-value syntax rules and the FIXML Schema syntax rules in the “FIX Protocol Syntax” section – FIX Tag=Value Syntax and FIXML Syntax.
