This regulation does not apply to residential SOS before the service periods specified in §C of this regulation. A utility may deny residential SOS under COMAR 20.50.04.01-2 or the utility's tariffs. A utility shall provide residential SOS for the following specified time periods: Baltimore Gas and Electric Company from July 1, 2006 through May 31, 2010; Delmarva Power & Light Company from July 1, 2004 through May 31, 2008; Potomac Electric Power Company from July 1, 2004 through May 31, 2008; The Potomac Edison Company doing business as (d/b/a) Allegheny Power from January 1, 2009 through December 31, 2012. Extension of SOS. The Commission may extend a utility obligation to provide SOS under Public Utilities Article, §7-510(c)(3), Annotated Code of Maryland.