For the purposes of this subchapter, the term: (a)(1) “Person” means an individual, corporation, firm, agency, company, association, organization, partnership, society, or joint stock company. (2) “Property line” means the line of demarcation separating privately owned property fronting or abutting a street or alley from publicly owned property on the other side of the line of demarcation. (3) “Public right-of-way” means the surface, air space above the surface, and area below the surface of any public street, highway, bridge, tunnel, alley, or sidewalk. (4) “Public space” means all the publicly owned property between property lines shown on the records of the District, and includes any roadway, tree space, sidewalk, or parking between such property lines. (5) “Respondent” means a person subject to a civil fine, compliance order, or abatement procedure as defined in § 50-921.19.