In Commonwealth ex rel. Maurer v. O'Neill, 368 Pa. 369, 83 A.2d 382, 43 Mun. L Rep. 73 (1951), the Supreme Court held a veterans' preference for promotion within the civil service unconstitutional, while the identical preference would be constitutional in the context of appointments. Our Supreme Court reasoned: The rules of statutory construction, require that words of a statute shall be construed according to their common and approved usage and to interpret the word "promotion" as synonymous with "appointment" would be to ignore this mandate. Webster's New International Dictionary (2nd Ed.) 1943, defines "promotion" as "the act of promoting", i.e. "to advance from a given grade or class as qualified for one higher" and "appointment" as "the designation of a person to hold an office". Authorities too numerous to mention offer similar definitions and none propose that the two terms are used interchangeably. Id. at 374-75, 83 A.2d at 384.