Section 4
SEC. 4. Paragraph (b) of section six of Republic Act Numbered Two hundred and ninety-one, otherwise known as the "Armed Forces Officer Personnel Act of Nineteen hundred and forty-eight," is hereby amended to read as follows: "(b) Whenever there are vacancies in any promotion list in the grade of first-lieutenant and captain, officers of that list in the grade of second-lieutenant and first-lieutenant may be promoted to and appointed in the grade of first-lieutenant and captain, respectively, before completion of three years' and seven years' service, respectively: Provided, That the number of years of service required for the purpose of subsections (a) and (b) of this section, as necessary for promotion in the Air Force, Navy, Judge Advocate General's Service, Chaplain Service, and the several corps of the Medical Service, shall be as the Secretary of National Defense shall prescribe."