In this chapter, the following terms have the meanings indicated. Terms Defined. “Applicant” means the person, partnership, association, corporation, or government agency applying for permanent telephone service, or developing a subdivision in which telephone service is to be provided to new residential buildings or mobile homes. “Commission” means the Public Service Commission of Maryland. “Mobile home” means a dwelling unit constructed for permanent occupancy, which is: Designed for moving along roads and highways by towing with a truck or tractor; and Installed on a permanent foundation. “Person” has the meaning stated in Public Utilities Article, §1-101, Annotated Code of Maryland. “Public service company” has the meaning stated in Public Utilities Article, §1-101, Annotated Code of Maryland. “Residential building” means a structure enclosed within exterior walls or fire walls, built, erected, and framed of component structural parts and designed for single-family occupancy. “Subdivision” means a portion of real property: Which includes or otherwise designates lots or locations intended for residential buildings or mobile homes including “planned unit developments” or “new towns”; and For which a new telephone distribution system is required in order to furnish telephone service therein. “Underground telephone distribution system” means that portion of a telephone utility distribution plant necessary to furnish permanent underground service to all present and anticipated residential buildings and mobile homes in a subdivision. The system includes underground telephone service lines as defined in §B(9) of this regulation. “Underground telephone service line” means that portion of a telephone utility distribution plant necessary to furnish permanent underground service from the lot line to a residential building or mobile home. “Utility” means a “telephone company” stated in Public Utilities Article, §1-101, Annotated Code of Maryland.