We consider holomorphic BF theories, their solutions and symmetries. The eq
uivalence of Cech and Dolbeault descriptions of holomorphic bundles is used
to develop a method for calculating hidden (nonlocal) symmetries of holomo
rphic BF theories. A special cohomological symmetry group and its action on
the solution space are described. (C) 2000 American Institute of Physics.
[S0022-2488(00)05505-5].