FIX 4.0 Specification
The FIX 4.0 specification includes significant enhancements over FIX 3.0.
Major changes in FIX 4.0 include enhancements in the following areas:
- Session layer
- Header information
- Supported encryption
- Date fields were modified
- Allocation support was significantly improved
Access to the Specification Documents: FIX Protocol Limited ("FPL") publishes the FIX Protocol specifications in Microsoft Word (".doc" or "DOC") and Portable Document Format (".pdf" or "PDF"). Any registered user of the FPL website may access the PDF version. Registration is free. Site users must be logged in to access specifications in either format.