63 STAT.] 81ST CONG., 1ST SESS.- CH. 146-MIAY 27, 1949 (3) The sale of material used in the construction, and of materials used in the repair or alteration, of real property, which materials, upon completion of such construction, alterations, or repairs, become real property, regardless of whether or not such real property is to be sold or resold. (4) The grant of the right to continuous possession or use of any article of tangible personal property granted under a lease or contract if such grant of possession would be taxable if outright sale were made; in such event such lease or contract shall be considered the sale of such article and the tax shall be computed and paid by the vendor upon the rentals paid. (b) The terms "retail sale", "sale at retail", and "sold at retail" shall not include the following: (1) Sales of tickets for admission to places of amusement and sports. (2) Sales of transportation and communication services. (3) Professional, insurance, or personal service transactions which involve sales as inconsequential elements for which no separate charges are made. (4) Sales of tangible personal property which property was pur- chased or acquired by a nonresident prior to coming into the District and establishing or maintaining a temporary or permanent residence in the District. As used in this subsection, the word "residence" means a place in which to reside and does not mean "domicile". (5) Sales of tangible personal property which property was pur- chased or acquired by a nonresident person prior to coming into the District and establishing or maintaining a business in the District. (6) The use or storage within the District of tangible personal property owned and held by a common carrier or sleeping-car com - pany for use principally without the District in the course of interstate commerce, or commerce between the District and a State, in or upon, or as part of, any train, aircraft, or boat. SEC. 202. "Purchase" and "purchased" shall mean and include- (a) any transfer, either conditionally or absolutely, of title or possession or both of the tangible personal property sold at retail; (b) any acquisition of a license or other authority to use, store, or consume, the tangible personal property sold at retail; (c) any sale of services sold at retail. SEC. 203. "Purchaser" means any person who shall have purchased tangible personal property or services sold at retail. SEC. 204. "In the District" and "within the District" mean within the exterior limits of the District of Columbia and include all territory within such limits owned by the United States of America. SEC. 205. "Store" and "storage" mean any keeping or the retention of possession in the District for any purpose of tangible personal prop- erty purchased at retail sale. SEC. 206. "Use" means the exercise by any person within the District of any right or power over tangible personal property and services sold at retail, whether purchased within or without the District by a purchaser from a vendor. SEC. 207. "Vendor" includes every person or retailer engaging in business in the District and making sales at retail as defined herein, whether for immediate or future delivery of the tangible personal property or performance of the services. When in the opinion of the Assessor it is necessary for the efficient administration of this title to regard any salesman, representative, peddler, or canvasser, as the agent of the dealer, distributor, supervisor, or employer, under whom he operates or from whom he obtains the tangible personal property sold or furnishes services, the Assessor may, in his discretion, treat and 125 Exemptions. "Purchase"; "pur- chased." "Purchaser." " In the District"; "within the Dis- trict." "Store"; "storage." "Use." "Vendor."