If you hit one of these keys, Emacs will believe that you hit that key in Emacs state. Except for novice users, C-c is also set to temporarily escape to Emacs and execute a command from the current major mode. See section Customization . C-z in Insert state will make Emacs think Meta has been hit. Escape to Emacs to execute a single Emacs command.
Q Q is for query replace.
By default, each string to be replaced is treated as a regular expression. V is similar, but will use a window different from the current window. Currently, ch can be one of c , C , g , q , and s . Emacs command M-l does the same for words. Emacs command M-u does the same for words.