EMA C++ RDM Usage Guide : 8 Market By Price Domain : 8.3 Data : 8.3.3 MapEntry.Key Contents
 
8.3.3 MapEntry.Key Contents
The MapEntry.Key’s data is a Buffer that contains a combination of the price and order side, thus each key is unique within its map. The MapEntry.Key’s data should be treated as a single entity and is not meant to be parsed.
MapEntry.Data is a FieldList that contains some or all of the following information about the price point:
Order Price & Side (BID, ASK, or ORDER_PRC and ORDER_SIDE)
Order Size (BIDSIZE, ASKSIZE, or ORDER_SIZE)
Number of aggregated orders (NO_ORD)
Quote Time (QUOTIM_MS)
A map containing the Market Makers (MMID) and optionally a field list with each of the market makers’ positions at the Order Price point.