Using OR groups lets you search for documents that match either this search criteria OR that search criteria. For example, you can search for all documents associated to the ProjectWise application MicroStation, OR all documents that were created after a certain date. You can also use OR groups to create a single search that contains more than one value for the same property or attribute. For example, say you want to find all documents associated to MicroStation and also those associated to AutoCAD. You would set MicroStation as your initial search criterion, then on the same search, add an OR group, set AutoCAD as the application, then run the search.