Boolean operators and wildcards can be entered into any of the advanced search boxes:
- ""
- A search within quotation marks targets the exact sequence of the search term’s characters, ie. "Briefe über Poesie".
- *
- An asterisk directly before or after a word fragment produces a search for all words which contain said word fragment, ie. the search Hannov* yields the result Hannover, Hannoveraner, Hannoverisch, etc.
- ?
- One can search for a word which may appear with various spellings by inserting one or more question marks into a word (a question mark stands in place of exactly one character), ie. a search for Po?sie yields the results Poësie and Poesie, or a search for se?n the results sein and seyn.
- AND
- One can search for various word combinations by using AND, ie. a search for Goethe AND Schiller produces a list of all documents in which both names appear.
- OR
- Documents in which at least one of the search terms appear can be found using OR, ie. a search of Tübingen OR Stuttgart produces a list of all documents which contain at least one of the entered names. Thereby one can also search for different variations of the name, ie. Hannover OR Hanover; Göthe OR Goethe.
- NOT
- One can rule out certain terms which should not be found in the targeted search area by using NOT, ie. a search of Schlegel NOT Friedrich produces all documents within the targeted search-area in which the name Schlegel, but not the name Friedrich appears.
These search operators and wildcards can be combined, ie. a search of: "Briefe über Poesie" AND Jena NOT Fried* yields all documents which contain the exact word sequence "Briefe über Poesie", at the same time contain the name Jena, but not a word that begins Fried*.
Proper names are distinguished in the register according to GND (Integrated Authority File) and are to be found in all previously distinguished documents by using GND spellings.