On Elektron, we have some RICs, such as USG2FN3040=TWEB and USGNFN3040=TWEB, which we believe use the Strategies Data Model. We can see the CUSIPs of the two instruments involved in these swaps by looking at the OFFCL_CODE and OFFC_CODE2 fields. However, we don't see how to programmatically determine which instrument is bought, and which instrument is sold, by buying the swap. Is there a field that has this information?