[ by Howard Haykin ] TO: Trading Permit Holders FROM: Business Development Division RE: Operational Systems Settings on The CBOE Business Development Division notified TPH's, or Trading Permit Holders, with information on operational system settings on volatility index product settlement days.  The only change from an earlier Regulatory Circular, #12-53, is the adjustment of the Opening Exchange Prescribed Width (OEPW) parameters for SPX options class series trading on the Hybrid 3.0 platform on days other than volatility index product final settlement days (see Regulatory Circular RG12-095). All other opening settings remain unchanged and are provided below for convenience. On the days when CBOE option series opening prices are used to determine the exercise settlement value for volatility index products, CBOE will modify certain operational systems settings for the option classes used to determine the exercise settlement value for that trading day only.  On all other trading days, these operational settings will return to the standard levels as detailed in regulatory circulars referenced below. CBOE Staff Contacts. Direct questions to:  Anthony Montesano at (312)786-7365, montesan@cboe.com; or CBOE Help Desk at (866) 728-2263 or  helpdesk@cboe.com. For further details, go to:  [CBOE RegCirc 12-94, 7/13/12].