Abstract The communication focusses on the different roles that oxides can play in multiphase oxidation catalysts. The explanation rests on the remote control effect, namely the creation or preservation of active and selective sites on Acceptor oxides thanks to the flow on their surface of spill-over oxygen emitted by separate Donor phases. The bond properties of Donors and Acceptors are discussed. Certain oxides may, according to the other oxides they are mixed with, play the role of Donors or Acceptors. It is speculated that optimal activity might necessitate a cooperation between Donor and Acceptor phase, the Donor/Acceptor mixtures being inherently better than mixed oxides with both abilities. Approximate scales of Donors and Acceptors are proposed.