Search engine operates in several modes, which are set switch "search rules".
search for an exact phrase (word)	We look for an exact match keywords (phrases), specified in the text. A similar extended query: "word1 word2"
search any of these words	We look for any of the words specified in the text of any termination. Words are separated by spaces. The same advanced search: word1* word2 *
search for all of the words	Searched for all words in the text box to any end. Words are separated by spaces. A similar extended query: + word1 + word2 *
advanced search	In this mode, you can search the individual words listed in the text. The words in the box separated by spaces. The search is conducted according to certain rules set out below.
Advanced Query Syntax
+	plus symbol before a word indicates that this word must be present on each search result
-	minus symbol before a word indicates that this word must not appear for all search results
*	asterisk at the end of the word indicates that the search should be made according to any end
""	double quotes are used to search the entire phrase , rather than individual words
Examples of advanced queries
air cargo	show results containing at least one of these words
+air +cargo	show results containing both of these words
+air -cargo	show results containing the word "air", but not containing "cargo"
air*	show results containing the words types of "air, airlines, aircraft"
+air +car* -care	show results containing the words types of "air, car" ..., but not containing the word "care"
"air cargo"	show results containing the phrase "air cargo", but not the "air Canada cargo"