Stock instruments are identified by field types and values within the field.
If the Product field is present in the Instrument block, and has the value 5 (EQUITY), the instrument is a stock.
If Product is not present, but Security Type is, and has the value CS or PS (Common Stock or Preferred Stock), the instrument is a stock.
If neither Product nor Security Type are present, but the CFICode field is, and the first character of the field is E (for Equity) and the second letter is one of S, P, R, C, F, or V, the instrument is a stock.
Otherwise, this is not a stock.
RAP - The Trading Edition does not support securities that offer multi-leg options.
See CFICode values at http://www.iso.org/iso/catalogue_detail?csnumber=32835 for full documentation.