Regulatory Release

Notice of Filing and Immediate Effectiveness of a Proposed Rule Change To Amend Exchange Rule 100, Definitions; Exchange Rule 503, Openings on the Exchange; Exchange Rule 515, Execution of Orders and Quotes; Exchange Rule 516, Order Types Defined; Exchange Rule 517, Quote Types Defined; Exchange Rule 518, Complex Orders; and Exchange Rule 521, Nullification and Adjustment of Options Transactions Including Obvious Errors