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The parameter to tag a command, host or service, is "poller_tag". If a check uses a "tagged" or "untagged" command in a untagged host/service, it takes the poller_tag of this host/service. In a "untagged" host/service, it's the command tag that is taken into accountconsideration.
The pollers can be tagged with multiple poller_tags. If they are tagged, they will only take checks that are tagged, not the untagged ones, unless they defined the tag "None".
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