Elements can be given non-unique names via the “Id”-input . It takes a list of strings as identifiers for beams. The default value is an empty string. Each beam has a name by default: its zero based index in the model. Identifiers provide a useful means to group the beams in order to modify or display them. In case one wants to give multiple names to an element use the notation '&"id1"|"id2"|"id3"|...' or shorter '&id1|id2|id3|...'. Similar to regular expressions this assigns the identifiers 'id1', 'id2', 'id3',... to a beam.