I want to use a different notification mail template for triggers with one and with two items (so I don't get the ugly UNKNOWN place-holders).

I tagged all my two-items triggers with tag '2items' and configured two actions:

• 'Report problems to Zabbix administrators', condition: 'Tag <> 2items'
• 'Report problems to Zabbix administrators (2 items)', condition: 'Tag = 2items'

Only the second action would ever be executed, the 'Tag <> 2items' never matches an event without any tags.

I took a peek into the source code and it seems that tag conditions are broken – the condition value is based on the first matching tag. It will never be 'SUCCEED' for event without any tags.