Four-fermion simulation at LEP2 in DELPHI

We present and discuss the generator setup for e+e- -> 4f processes chosen by the DELPHI collaboration. The need to combine the most recent theoretical achievements in the CC03 sector with the state of the art description of the remaining part of the 4-fermion processes has led to an original combination of different codes, with the WPHACT 2.0 4-fermion generator and the YFSWW code for the CC03 O(alpha) corrections as a starting point. The coverage of the 4-fermion phase space is discussed in detail, with particular attention to ensuring the compatibility of WPHACT with dedicated gamma-gamma generators.