KARACHI - The SBP will start issuing Rs 20 commemorative coin through the exchange counters of all the field offices of SBP Banking Services Corporation from May 28 on the occasion of 150 year celebrations of Lawrence College, Ghora Gali, Murree, the SBP said. It may be added here that all the field offices of SBP Banking Services Corporation have been issuing Rs 20 commemorative coin to commemorate the 60th anniversary of establishment of diplomatic relations between Pakistan and China as well as to celebrate the 2011 Year of Pak China Friendship since May 21.