Russia bank account number validations

Does anyone have an official source outlining requirements for validating the combination of Russia banks with bank account numbers.

SAP has put a validation algorithm in function module FI_CHECK_BANK_ACCOUNT_RU. But, I cannot find anything in OSS or online that supports having this validation in place.

This algorithm uses the last three positions of the bank number, the control key, and the bank account number to determine validity.

My business contacts are indicating that banking information given to them by our vendors are failing this validation.