The search below would limit an "alert" tag to the "host" field.
tag::host=alert
The search does the following:
* It uses tag syntax to filter events by tags. Tags are custom labels that can be applied to fields or field values to provide additional context or meaning for your data.
* It specifies tag::host=alert as the tag filter. This means that it will only return events that have an "alert" tag applied to their host field or host field value.
* It uses an equal sign (=) to indicate an exact match between the tag and the field or field value.