The collection concept is a special feature of RWTH Publications. Collections are logical data volumes which can be used to filter the data pool. The RWTH Publications home page has a corresponding search field as well as a list of the various collections which reflect the structure of RWTH Aachen University. In the default setting, all the collections are activated. If one or more collections are selected, the search is only carried out in the corresponding data pool. Once a search has been made, it can be broadened to include other collections. After a search has been started, the results are sorted into collections and displayed.