I am currently in the process of clearing a backlog of QSL cards which arrived from the RSGB QSL Bureau over a month ago.
I wish to let fellow SOTA chasers and activators know via the SOTA reflector that whilst I do collect QSL cards and return them to senders via the RSGB bureau, from now on I will only send a return QSL to confirm a band slot or a mode slot for any station who sends me a card the one time. If I operate outside of England which I do several times a year, then the same rule will apply, you will get a QSL confirmation for a contact with GW4OBK/P and G4OBK/P etc one time each for each band / mode slot for all countries I operate from. So if you worked me on 20m CW as G4OBK twice on that band - mode in 2014 and in 2015 you will only receive one QSL for first QSO completed.
This QSL policy is to reduce the sending of more cards than I need to - with an eye on the cost of printing and postage in particular.
73 de Phil G4OBK