The mask passed to Who is matched against a users' host,
real name or nickname. It uses the wildcard system of matching
where the '*' can stand for any number of characters and '?' stands for any single
character. The query will only match against one component so it is not possible
to match against both nick and host for example.
True if the query should only try to match the mask
to users designated operators.
//Find all users from Russia, i.e. who have .ru in their hostnames
connection.Sender.Who("*.ru", false );
//Find all users from clan [DX], i.e. have '[DX]' in their nick
connection.Sender.Who("[DX]*", false );