Exceptionally the railways unified as C.S.A.R. (Central South African Railways) chose not to use franking privileges, overprinted lower values of postage stamps with these initials. Evidence of their forgery for collectors, even by employees and their cost to the General Post Office led to their abandonment. Not common on single stamps, they are rare on cover. The cover with torn stamp below shows that it was not for collectors, but nevertheless acceptable to the GPO. On official stationery, it passed through Hillbrow the nearest post office to its destination.