English to French Other Finance (general)

"where a full structure chart is not available to identify/verify the IOs, acceptable sources (as defined in the ID&V Matrix) can be used to identify/ verify the UBOs without obtaining IOs between the Customer and the Corporate Parent."

Any idea as to what IOs stands for here?

ID&V is "identification and verification".
UBO is "ultimate beneficial owners"

These are banking regulations regarding the analysis of the property structure of corporate clients.