The structured operators and corresponding operator identities, which appear in inverse problems for the self-adjoint and skew-selfadjoint Dirac systems with rectangular potentials, are studied in detail. In particular, it is shown that operators with the close to displacement kernels are included in this class. A special case of positive and factorizable operators is dealt with separately. MSC(2010): 45H05, 47G10, 34L40, 47A68.