Plug-ins for querying catalogues have been available in Goobi since 2009, although until now it has always been sufficient to query a single record from a catalogue using a specific identifier. However, in one of the most recent projects in which we were involved, it became clear that there was also a need for more complex queries. Specifically, depending on the catalogue selection, one, two or even three identifiers should be used together in the catalogue query to obtain a concrete record. For this reason, the interface for Opac plugins had to be extended in such a way that such plugins can now control an additional area in which further entries should be possible. In the case of the JSON Opac plugin, this has been put into productive operation and the interface is now different from the Opac plugins of the past. In addition to the input of an identifier at least one line with additional information is now possible.