The recently developed hidden crossings approach to slow atomic collisions is applied to inelastic processesinvolving inner-shell electrons. The hidden crossing theory reveals new mechanisms for inner-shell vacancy creation and transfer which are associated with the S- and Q-superseries of hidden crossings of adiabatic energy surfaces in the complex plane of internuclear distance. The properties of these new electron transition mechanisms are explored and compared with some of the conventional mechanisms (rotational, Demkov and Landau-Zener coupling). The theory is illustrated by probability and cross section calculations for vacancy creation and transfer in specific collision systems.