OPI No. X

Italian to English Bus/Financial Finance (general) Financial Reports

As in "Orientamenti preliminari Assirevi in tema di IFRS (OPI N. 1). etc.

Mine is OPI 2. I have the feeling it might mean "Circular No. 2" but I am finding that few people appear to translate it.

(I know what IFRS stands for International Financial Reporting Standards etc.)

My question is what words do the letters OPI stand for?