After visiting LSE's Alumni section  site I was confused what does ALUMNI word really stand for, When Deuba was neither student nor staff of (Only Library Card holder) then how can LSE list his name so proudly in ''WORLD LEADERS, LSE alumni and Staff''.?

It seems like LSE is more concerned about him, and they are proud that a person holding (in past) an  LSE library card could make a head of government 3 times. To reconfirm myself, I double checked the meaning of ALUMNI in dictionary  which said ''Former Students of institution''. Does one can be an alumnus/alumna without being officially registered in institution, such as independent researcher/taking summer course/ attending seminar etc? If so he surely is an alum, otherwise ........!!!

Just my two cents, do correct if Im wrong.