On September 21st, a proposal by C2 Options Exchange, Incorporated related to the Exchange's Automated Improvement Mechanism was granted immediate effectiveness. C2 Rule 6.51 governs the operation of an exchange feature that allows agency orders to electronically execute against principal or solicited interest pursuant to a crossing entitlement after being exposed in an auction. The purpose of this proposed rule change is to provide the exchange with the ability to determine to apply a price-time priority allocation algorithm for the SPXPM option class, subject to certain conditions. Comments should be submitted on or before 21 days from publication in the Federal Register, which is expected the week of September 26th. SEC Release No. 34-65371.