Pakistan in the United Nations, the Commonwealth and the World Trade Organization
Background
The United Nations list of Member States gives Pakistan's date of admission as 30-09-1947.
The Commonwealth records that Pakistan joined in 1947, on partition from India; left in 1972, rejoined in 1989.
It is therefore one of the members that has left the association and later returned to it.
The World Trade Organization records that Pakistan has been a WTO member since 1995.
The same record shows Pakistan as a member of GATT since 30 July 1948, under the trading system that the WTO later replaced.
In plain words
GATT General Agreement on Tariffs and Trade — The post-war trade agreement that governed world trade rules until the World Trade Organization took over.
Commonwealth — A voluntary association of independent countries, most of them with a shared constitutional past.