+ A plus sign indicates that this word must be present in every row that is returned.

- A minus sign indicates that this word must not be present in any of the records that are returned.

* The asterisk substitutes any character or group of characters. It should be added to the word concerned.

" A phrase in double quotes matches only records ('"') containing the exact words of the sentence and in the same order.

( ) Parentheses are used to group words into subexpressions. The groups can be nested parentheses.

Examples:

catalunya tarragona	Finds rows that contain at least one of the two words.
+catalunya +autonomia	Finds rows that contain both words.
+catalunya autonomia	Finds rows that contain the word "catalunya", but better classification that also contain "autonomia".
+catalunya -autonomia	Finds rows that contain the word "catalunya" but not "autonomia".
catalu*	Finds rows that begin with "catalu": "catalunya", "cataluña", o "catalunha".
"autonomia de catalunya"	Finds rows that contain the exact phrase "autonomia de catalunya" (for example, "Constitució Espanyola. Estatut d''Autonomia de Catalunya. Reglament del Parlament de Catalunya." But not "La financiación de la autonomia catalana : Palabras del Presidente Catalunya en el Colegio de Economistas de Catalunya").
(+espanya -autonomia) (+catalunya +autonomia)	Finds rows that contain the word "espanya" but not "autonomia", or those with the two words: "catalunya" and "autonomia".