Within the low-traffic Usenet newsgroup alt.xyzzy, the word is used for test messages, to which other readers (if there are any) customarily respond, "Nothing happens" as a note that the test message was successfully received. In the Internet Relay Chat client mIRC and Pidgin, entering the undocumented command "/xyzzy" will display the response "Nothing happens". The string "xyzzy" is also used internally by mIRC as the hard-coded master encryption key that is used to decrypt over 20 sensitive strings from within the mirc.exe program file.