FIX-4-17 is the revised version of FIX-4.0, which is a protocol specification for a certain type of electronic trading. It is primarily used for trading in financial instruments over the Internet, as well as for other types of electronic transactions.
The protocol consists of a series of message types that are used to send, receive and confirm information on trades, orders and other exchanges between the buyer and the seller, as well as the exchange of financial products. The main components of FIX-4-17 are message types, tagging & delimiting, session state, application sequences, message data dictionaries and message validation rules. FIX-4-17 also includes support for advanced features such as encryption and early termination of messages.