No. 39 (00131) Family name : Was Given name : Zbigniew Affiliation : Institute of Nuclear Physics Cracow Abbreviation : HNINP E-mail address : zbigniew.was@cern.ch Title : Observables with tau leptons at LHC and LC, structure of event records and Monte Carlo algorithms Authors : Z Was Abstract : In the construction of Monte Carlo physics generators, question of data structures used for communciation between parts is important. Using as an example, the TAUOLA universal interface and PHOTOS on one side, and HERWIG and PYTHIA on another, I will present the technical details of practical solutions. On the other side I will adress the question, how sufficiently complete implementation of spin effects into processes which generation need to be covered by programs written by distinct authors can be helpful in designing the observables for Higgs boson searches or measurement of its parity.