On signal
From Scriptwiki
The on signal event triggers if a script has used the /signal command to send a signal to all scripts.
on *:SIGNAL:name:command
The signal name can contain wildcards.
The $signal identifier returns the signal name that caused the signal event to trigger.
The $1- identifier returns the parameters that were specified in the /signal command.
Note: The script that called /signal is triggered first, and then all other scripts are triggered.
Example
on *:SIGNAL:load:hmake database 100 | if ($isfile(database.hsh)) hload database database.hsh
When the "load" signal is triggered, creates a hash table and loads data into the hash table if available.