Under which constitution of Pakistan Islamabad was confirmed as the capital of Pakistan?

Under which constitution of Pakistan Islamabad was confirmed as the capital of Pakistan?

Explanation

Article 1(2)(b) of the Constitution of the Islamic Republic of Pakistan, 1973 declared the status of Islamabad Capital 

Islamabad officially became the capital of Pakistan on 14 August 1967.

Ayoub Khan made Islamabad the capital of Pakistan

The area before its declaration as the capital of Pakistan was known as Raj Shahi.

Islamabad is the country's ninth-most populous city, with a population of over 1.2 million people

The name Islamabad means City of Islam.

Islamabad Constructed 1960