Content matches are case-sensitive by default, but the
nocase content modifier tells Snort to ignore case and look for the specified string match case-insensitively.
# It is common to see nocase used with `fast_pattern` content:"super_secret_encryption_key",fast_pattern,nocase;
nocaseoption also applies to hex bytes; specifying
content:"|41|",nocase;will look for either 'A' or 'a' in the packet.