From 1871 to 1886 certain Oxford and Cambridge colleges issued their own stamps to be sold to members of the college so that they could pre-pay the cost of a college messenger delivering their mail.
The practice was stopped in 1886 by the General Post Office as it was decided that it was in contravention of its monopoly.
The colleges which issued the stamps were:
Postal stationery was also used by some of the colleges listed above (post cards, envelopes) which were impressed with a pre-paid stamp. This is denoted by # above and in some cases postal stationery was in use for several years before stamps came into use, for instance at Hertford College.