In order to reduce the multitude of data for transmitting and converting use authorizations, which are received either encoded or non-encoded together with sound and/or picture contents in signals from optional networks, it is proposed to reduce the hierarchically structured use authorization information in the form of a tree structure before transmitting it further, such that non-occupied tree branches are detected and marked as not relevant, wherein the tree branches marked as not relevant are not included during the further transmitting of the use authorization information.