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---------------------------- The difficult task of choosing the best settings for a calculation problem is made much easier by the existence of several "pre-packaged" sets of defaults, each of which is optimised for a particular type of application. Each set is chosen by option DEFAULTS, which has to be placed at the beginning of the input file, possibly preceded only by TITLE or GLOBAL. Several possibilities include hadrotherapy, calorimetry, pure electromagnetic runs without photonuclear reactions, low-energy neutron runs without gamma production, and others. One set of defaults is tuned for maximum precision (but not necessarily great time efficiency). Reasonable defaults, acceptable for most generic routine calculations, are provided in case DEFAULTS is missing. In most cases, the user has the possibility to use some of the other setting options described below, to override one or more of the defaults provided by the chosen set. In any case, it is important to check the list of defaults to make sure that nothing important is missing or has been overlooked. For instance, photonuclear reactions, which are critical for electron accelerator shielding, are not provided by any of the available default sets and must be added by the user by means of the PHOTONUC command. Another setting option, DISCARD, is used to indicate particles which shall not be transported. The energy of those particles is not deposited anywhere but is added up in an accumulator which is printed at the end of the FLUKA standard output. Of course it is the user's responsibility to see that the discarded particles and their progeny would not give a significant contribution to the requested results.