EMA C++ Developers Guide : 3 OMM Containers and Messages : 3.3 Working with OMM Containers
 
3.3 Working with OMM Containers
Enterprise Message API supports the following OMM containers: ElementList, FieldList, FilterList, Map, Series, and Vector.
Each of these classes provides set type interfaces for container header information (e.g., dictionary id, element list number, and the add-type interfaces for adding entries). You must set the container header and optional summary before adding the first entry.
Though it is treated as an OMM primitive, the OmmArray acts like a container and therefore provides add-type interfaces for adding primitive entries.
 
NOTE: OMM Container classes do perform some validation of their usage. If a usage error is detected, an appropriate OmmException will be thrown.