\x This lets You insert any value into string. "\x" MUST be followed by two digits describing HEX number which is the number of ASCII char You want to put there. You will have "ERROR: Unknown HEX number following \x" if You do something wrong. \! This will insert a BELL ($07) char to Your string. When You put this char to console, screen will flash \v This inserts a vertical tabulator ($0B)