For target and recoil polarization in pion electroproduction the following coordinate systems are used in the literature: all frames are in the center of mass: ===================================== 1) {1,2,3} in the scattering plane: 3 : photon (k) identical to z 2 : = ki x kf perpendicular to the scattering plane of the electron 1 : = 2 x 3 2) {x,y,z} in the reaction plane: z : in the direction of the virtual photon (k) y : = k x q perpendicular to the photon (k) and the pion (q) x : = y x z in the reaction plane of pion and photon 3) {x',y',z'} in the reaction plane: z' : in the direction of the pion (q) y´ : = k x q identical to y x' : = y' x z' in the reaction plane of pion and photon 4) {t,n,l} in the reaction plane: l : in the direction of the outgoing nucleon (-q) n : = k x q identical to y t : = n x l in the reaction plane of pion and photon Note: Only system 1) is independent of the pion and nucleon in the final state. These is the only systems which can be used in inclusive reactions. For the Response Functions we use 2) for both target and recoil polarization For the Transverse Polarization Observables we use 2) for target and 3) for recoil polarization in accordance to the standard definition in pion photoproduction For the Target- or Recoil Polarization Programs any one of systems 1) - 4) can be selected. For integrated cross sections we will use system 1).