Sec. 1. Any provision of existing law to the contrary notwithstanding, the following guidelines shall be observed in the call of Active Duty and Extensions of Active Duty of Reserve Officers:
a. A reserve officer will be initially called to active duty for a period of three (3) years. Upon satisfactory completion of his tour of active duty, it shall be extended for a period of another three (3) years.
b. A reserve officer who has satisfactorily rendered six (6) continuous years of active military service shall, upon satisfactory completion of his extended tour of active duty, be granted another extension for a period of four (4) years.
c. A reserve officer who has satisfactorily rendered a total of ten (10) years of continuous active commissioned military service shall not be reverted to inactive status, except upon his own request or for cause as may be adjudged by a court martial or by appropriate bodies existing by provisions of law or by virtue of the operation of Presidential Decree No. 1638 which provides for the forced attrition of officers based on exigencies of the service, up to the time he reaches the compulsory retirement of thirty (30) years of service or fifty six (56) years of age, whichever comes later, but not later than sixty (60) years of age.