There is a special category of triggers where recovery notifications don't make any sense. Examples are one-time events like "/etc/passwd has changed", "zabbix agent version changed" or "Host {HOSTNAME} rebooted". You simply don't want an OK notification that tells you that the host did not reboot anymore since the last check.

Now that zabbix already features trigger tags since 3.2, adding an optional filter condition to recovery and acknowledgement operations would solve the problem:

A tag like T_NO_RECOVERY could be added to the corresponding triggers and the recovery operation of the actions could be configured with a condition like Tag <> T_NO_RECOVERY.

This feature request is a more specific version of ZBXNEXT-582, since trigger tags are already implemented now but a filter condition in the recovery operation is still missing.