In this chapter, the following terms have the meanings indicated. Terms Defined. “Affidavit” means a sworn statement in writing on a standard form furnished by the Department. “All persons residing in the home” means household occupants as of the date an application is submitted. “Applicant” means a person filing for a property tax credit. “Combined gross income of all persons” means the monies received in the prior calendar year by the applicant homeowner, the spouse, unless separated, divorced, or widowed, or the resident co-owner, or all of these, and the monies received by other nondependent occupants of the household unless they are paying reasonable fixed charges. “Combined net worth” means the net worth of the applicant, spouse or co-owner, or all of these, residing in the dwelling house. “Curtilage” means that amount of land necessary and used for the homesite and dwelling. “Dependent” means a person who satisfies the federal Internal Revenue Service standard for a dependent. “Dwelling house” means the principal residence of a homeowner but does not include any portion of the structure used for a business or income-producing purpose. “Principal residence of the homeowner” is the one dwelling house where the homeowner regularly resides and is the location designated by the owner for the legal purpose of voting, obtaining a driver's license, and filing income tax returns. “Reasonable fixed charges” means the amount of room and board, rent, or expenses paid which are sufficient to defray the cost of an individual residing on the premises. “Total income” means all monies received by a person in a given year, whether taxable for federal or State income tax purposes, or not.