"Remaining a fair player, The Royal Society ensures that published open access articles bearing a publication fee are deducted from subscription prices through its Transparent Pricing Mechanism"

The Royal Society thereby pledges that it will not "double-dip" for hybrid Gold OA. The RS continues to collect subscription fees from institutions worldwide, but whatever additional revenue if gets from individual authors for hybrid Gold OA, it pledges to return as a subscription rebate to all subscribing institutions.

But does this mean the RS is a "fair player" insofar as OA is concerned?

Hardly.

Yet this is not because the hybrid Gold OA rebate amounts to individual authors' full payments for Gold OA subsidizing the subscription costs of institutions worldwide. (The author's own institution only gets back a tiny fraction of its authors' Gold OA fee in its tiny portion of the worldwide subscription rebate.)"