Here is the code we use in our INIT section. For tracking purposes, which is probably overkill, each rule issues a WTO when enabled or disabled. While the WTO may be overkill, I will say it has come in very handy when coding and debugging a rule as you can easily see when the rule was disabled and enabled in the log so you know where to look for any responses or other diagnostic information. I also have a rule which will highlight any message with "ABLE00" on the end.
curr_system = OPSINFO('SYSNAME') /* The Current System */
exec_system = "XXXX" /* The Desired System */
curr_rule = OPSINFO('PROGRAM') /* The Current Rule */
IF curr_system = exec_system THEN DO
z = OPSVALUE('GLOBAL1.ENABLE.RULE.'curr_rule,'U','TRUE')
wto_txt.1 = "Rule" OPSINFO('PROGRAM') "is enabled."
msg_id = "ENABLE00"
ADDRESS WTO "TEXTVAR("wto_txt.") MSGID("msg_id")"
RETURN 'ACCEPT'
END
ELSE DO
z = OPSVALUE('GLOBAL1.ENABLE.RULE.'curr_rule,'U','FALSE')
wto_txt.1 = "Rule" OPSINFO('PROGRAM') "will not be enabled."
msg_id = "DEABLE00"
ADDRESS WTO "TEXTVAR("wto_txt.") MSGID("msg_id")"
RETURN 'REJECT'
END