1. use AND to make all search terms inclusive (onions AND celery: all cases containing both 'onions' and 'celery')
2. use OR to search for any of the terms (onions OR celery: all cases containing either 'onions' or 'celery')
3. not providing any Boolean operator implies AND (onions celery: same as #1 above)
4. note that OR binds more tightly than AND between adjacent terms (onions OR celery salt: all cases containing either 'onions' or 'celery', plus also the cases containing the term 'salt')
5. - excludes the term (onions -celery: all cases containing 'onions' but not 'celery')
6. phrase in quotes ("onions celery": all cases containing 'onions celery' exactly as shown)