The filter allows limit of results list: display only those strings in which there is specified substring; or display all strings except those in which there is a specified substring.
Split different substrings by semicolon.
M: — Search Mail.ru,R: — Rambler,Y: — Yandex,G: — Google,N: — Nigma.ru,Q: — Qip.ru,H: — Yahoo!,B: — Bing.com,D: — DuckDuckGo,BD: — Baidu