53 Pa. Stat. § 42001
The following words and phrases, unless a different meaning is plainly required by the context, shall have the following meanings:--
"Person," an officer or employe of the city.
"Employe," a person in the service of the city, who is either, or who is not now adequately protected under all circumstances by pensions authorized by the laws of this Commonwealth and in force at the time of the passage of this act.
"Officer," a person elected or appointed to city service.
"Board," Officers and Employes Retirement Board.
"City" or "Cities," all third class cities adopting this act.
"Fund," Officers and Employes Retirement Fund.
"Compensation," retirement allowance or compensation.
"He," the masculine and feminine pronouns.
"Joint Coverage Member" of the retirement system shall mean a city employe who shall have become a member of the retirement system subsequent to the last date permitted by such city for statement of preference concerning social security coverage, or who, having become a member on or before such date, shall have filed with the Retirement Board a written statement that he or she elects Social Security coverage under an agreement with the Federal Secretary of Health, Education and Welfare entered into by the Commonwealth.
"Single Coverage Member" of the retirement system shall mean a city employe who shall have become a member of the retirement system on or before the last date permitted by such city for statement of preference concerning social security coverage, and who either shall have filed with the Retirement Board a written statement that he or she does not elect social security coverage under any agreement with the Federal Secretary of Health, Education and Welfare entered into by the Commonwealth, or shall not have filed with the Retirement Board any written statement.
"Years of Service" shall include any time not exceeding six years spent by the employe on active duty with the armed forces of the United States, providing that he received an honorable discharge or a certificate of satisfactory service and he pays to the board an amount equal to three per centum of his last monthly salary or wage prior to entering on active duty for each month he is not employed by the city because of his active duty with the armed forces.
53 P.S. § 42001