The Canadian Securities Administrators (CSA) published its methodology for overseeing market data fees on Thursday in the wake of ongoing complaints about the costs of market data.

Although the CSA adopted a formal methodology for assessing each marketplace’s data fees in April, it has now published a notice that spells out the methodology and provides guidance on how it’s applied to the various markets.

“The purpose of this notice is to provide marketplaces and marketplace participants with information about the scope, application, implementation and use of the data fees methodology,” the CSA says in its notice.

The methodology estimates a fee, or a fee range, for each marketplace based on its contribution to price discovery and trading activity, according to the notice, and has already been applied to most markets’ fees.

The methodology is applied to new fees, changes to existing fees, and in annual reviews of market data fees. The next annual review is slated for February 2017.