In cricket, a batsman retires out if he retires without the umpire's permission, and does not have the permission of the opposing captain to resume his innings(kindly note its not a method of getting out). How many batsman have retired out in Test match cricket?

In cricket, 'retired out' is a dismissal where a batsman leaves the field without the umpire's permission and cannot return to continue their innings. This is different from 'retired hurt' where the batsman can resume later. In the entire history of Test cricket, only two batsmen have been dismissed 'retired out' - Marvan Atapattu of Sri Lanka in 2001 and another instance. This remains one of the rarest forms of dismissal in the game.