"The ASCII characters 6, 7, 8, 9, and , are not used to represent anything in NetHack by default, although , is the pick up command. You can also use the keys 0\u20139 to specify a numeric prefix for a command or in a menu. Some players change the \"monsters\" option in the options file to take advantage of one of these unused symbols. A default line looks like: OPTIONS=monsters:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@ '&;:~] One alternative is: OPTIONS=monsters:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@8'&;:~]"@en . . . . . "The ASCII characters 6, 7, 8, 9, and , are not used to represent anything in NetHack by default, although , is the pick up command. You can also use the keys 0\u20139 to specify a numeric prefix for a command or in a menu. Some players change the \"monsters\" option in the options file to take advantage of one of these unused symbols. A default line looks like: OPTIONS=monsters:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@ '&;:~] One alternative is: OPTIONS=monsters:abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ@8'&;:~] which uses \"8\" for ghosts and shades. This makes them detectable via telepathy as well as generally easier to see."@en . "Unused symbols"@en .