guard

When guard is on, unprintable control characters are discarded. Non-ASCII characters, or characters with the high bit on, are stripped to seven-bit characters (and discarded if they are control characters). Only these control characters are permitted:
 

backspace (control-H)	carriage return (control-M)	linefeed (control-J)
bell (control-G)	formfeed (control-L)	tab (control-I)

The guard option prevents unprintable characters from doing undesirable things to your monitor (such as locking the keyboard, entering graphics mode, or entering transparent print mode). It also makes your get file more suitable for opening with a word processor.

The guard option should not be used when you need to receive control characters for screen formatting (such as when using terminal emulation) or when using software on the remote system that needs to control your screen for fancy screen displays.