[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] [X] [Z] ! (logical NOT) operator matching IP addresses and ports for Snort rules TCP flag matching, Snort rules <> (direction operator), in Snort rules * operator, TCP flag matching in Snort rules + operator, TCP flag matching in Snort rules -> (direction operator), in Snort rules -nolisten tcp option for startup commands ../ character sequence in requests .rej files, finding /dev/mem and /dev/kmem, preventing access to /proc directory, restricting access with grsecurity : (colon), in port ranges for Snort rules | character enclosing hexadecimal vales in Snort rules searching on multiple variables |