1. A computer-implemented method of indexing a database of documents, a subset of the documents containing nested fields, each nested field having an associated start meta word and end meta word, each meta word having an associated nesting level, the method comprising: indexing each document containing nested fields by: parsing the document to determine locations within the document of words and meta words in the document and to determine the nesting level associated with each meta word; and generating an index including word entries, each word entry identifying locations within the document of an identified word; meta word entries, each meta word entry identifying locations within the document of an identified meta word and indicating the determined nesting level associated with the meta word; and generic meta word entries, each generic meta word entry identifying locations within the document of a class of meta words, including meta words at all nesting levels of the meta words found in the document, the generic meta word entry including, for each identified location within the generic meta word entry, information identifying the nesting level associated with the meta word at the identified location.