All documents which contain one of the word from query criteria "any word" will be result of such search. For example, in query criteria "book audit" on the result of search we shell have documents with words "book" or "audit" as well as "book", "bookkeeper", "bookkeeper's", "auditor", "auditor's" and so on.

If the query criteria was "all words", we shell have documents contain words "book and audit" or "bookkeeping and auditing service" simultaneously.

All symbols different from numders or letters are replaced with blank. Words which contain less then three letters don't take part in search. Search don't respond to the letter case.