The MarketDataStatisticsRequest(35=DO) is used to request for statistical data. The simple form is to use an identifier (MDStatisticID(2475)) assigned by the market place which would denote a pre-defined statistical report. Alternatively, or also in addition, the request can define a number of parameters for the desired statistical information.
Additional detail from the official source
The resulting data set can be restricted to a specific market, market segment or pre-defined security list for which a single set of statistics will be returned. It is also possible to specify individual instruments or group of instruments by means of the component blocks Instrument, UndInstrmtGrp and InstrmtLegGrp.
Fields specified in the request are used as filter criteria to restrict the resulting data returned.
Message structure 4006 distinct fields
Source order, including nested components and groups. Group counts precede the repeated entries. “Required here” is relative to the enclosing component or group, not unconditional in the message. A dash means not marked required; conditional requirements remain in the source notes. This is a reference, not a counterparty-specific validator.
Includes nested components and groups. Escape clears the filter.