A way of limiting a result of a query to those occurrences which
    match certain characteristics. You can select the following
    attributes: NAME, SYMBOL_CLASS, OCCURRENCE, DOMAIN, or FILE_SPEC
    attributes. In the query language, you use phrases like name=foo,
    symbol=argument, occurrence=declaration, domain=module_specific,
    and file="foo.c" to specify which attributes you want. You combine
    these phrases with AND, OR and NOT operators.