EMA C++ Developers Guide : 3 OMM Containers and Messages : 3.4 Working with OMM Messages
 
3.4 Working with OMM Messages
Enterprise Message API supports the following OMM messages: RefreshMsg, UpdateMsg, StatusMsg, AckMsg, PostMsg and GenericMsg. As appropriate, each of these classes provide set and get type interfaces for the message header, permission, key, attribute, and payload information.