I am currently implementing a CQL Parser for .NET / C#. When I studied the BNF in the CQL spec, I found something which does not make sense to me. The spec says: term ::= identifier | 'and' | 'or' | 'not' | 'prox' | 'sortby' this means that the words and, or, not, prox and sortby are valid terms. The spec also says that prefix, uri, modifierName, modifierValue, searchTerm, index ::= term this means that the words and, or, not, prox and sortby are valid as prefix, uri, modifierName, modifierValue, searchTerm and index. Putting all this together, it means that the following strings are all valid CQL Queries: and and and and and or not and or not and dino and not not and Is this an error in the CQL spec? Kind Regards Matthias