(B) an individual first employed by the government of the District of Columbia before October 1, 1987; but does not include
(i) a teacher or librarian of the public schools of the District of Columbia;
(ii) a part-time employee who does not have an established regular tour of duty during the administrative workweek;
(iii) a temporary employee engaged in construction work at an hourly rate;
(iv) an employee of the Panama Canal Commission when employed on the Isthmus of Panama;
(v) a physician, dentist, or nurse in the Veterans Health Administration of the Department of Veterans Affairs;
(vi) an employee of either House of Congress or of the two Houses;
(vii) an employee of a corporation supervised by the Farm Credit Administration if private interests elect or appoint a member of the board of directors;
(viii) an alien employee who occupies a position outside the United States, except as provided by section
6310 of this title;
(ix) a teacher or an individual holding a teaching position as defined by section
901 of title
20;
(x) an officer in the executive branch or in the government of the District of Columbia who is appointed by the President and whose rate of basic pay exceeds the highest rate payable under section
5332 of this title;
(xi) an officer in the executive branch or in the government of the District of Columbia who is designated by the President, except a postmaster, United States attorney, or United States marshal;
(xii) a chief of mission (as defined in section 102(a)(3) of the Foreign Service Act of 1980); or
(xiii) an officer in the legislative or judicial branch who is appointed by the President.