The OAI indexing example defines many different index
    names, a study of the conf/oai2index.xsl
    stylesheet reveals the following word type indexes (i.e. those
    with suffix :w):
    
     any:w 
     title:w
     author:w
     subject:w
     description:w
     contributor:w
     publisher:w
     language:w
     rights:w
    
    By default, searches do access the any:w index,
    but we can direct searches to any access point by constructing the
    correct PQF query. For example, to search in titles only,
    we use
    
     http://localhost:9999/?version=1.1&operation=searchRetrieve&x-pquery=@attr
     1=title the&startRecord=1&maximumRecords=1&recordSchema=dc
    
   
    Similar we can direct searches to the other indexes defined. Or we
    can create boolean combinations of searches on different
    indexes. In this case we search for the in
    title and for fish in 
    description using the query 
    @and @attr 1=title the @attr 1=description fish.
    
     http://localhost:9999/?version=1.1&operation=searchRetrieve&x-pquery=@and
     @attr 1=title the
     @attr 1=description fish&startRecord=1&maximumRecords=1&recordSchema=dc