FIX-3-4.5 is a standard publication which defines the format and content of messages (or protocols) used in the financial services industry between member firms, exchanges and clearing houses. It is a revision of FIX 4.0 and is used in equity, options, futures, foreign exchange and money market securities. The FIX-3-4.5 version consists of numerous message types, including order entry messages, execution messages and administrative messages, as well as a table of values to represent various objects within the message. The text includes instruction on how to send and receive messages, and what to do if errors are encountered.