Definition
IIROC was the SRO that regulated Canadian investment dealers and trading on Canadian equity marketplaces from 2008 until December 31, 2022. On January 1, 2023 it amalgamated with the MFDA, and the combined SRO took the CIRO name on June 1, 2023. References to IIROC rules in older materials map roughly to CIRO IDPC and UMIR rules today.
Source
Recognition orders, predecessor SRO archives