  The smallness of the transverse dimensions of the colliding beams leads to
suppression of bremsstrahlung cross section. This beam-size effect was
discovered and investigated at INP, Novosibirsk. Different mechanisms of
radiation are discussed. Separation of coherent and incoherent radiation is
analyzed in detail. For linear collider this suppression affects the whole
radiation spectrum. It is shown that objections to the subtraction procedure in
\cite{BK2} are groundless.
