Searching is not case-sensitive. Otherwise the search looks for complete words. Searching starts at the beginning of a word. You can't look for segments in the middle of words.
Parentheses force a search order.
Searching for phrases is not supported. They are useful to know if you wonder why some word you are searching for never seems to come up. Indexed words must have at least 3 characters. Long words are truncated after the 30th character. Accented letters are converted to their unaccented equivalent.