What does the "Null" option mean in my Analytics filter?

Question

What does the "Null" option mean in the Analytics filter on my dashboard?

Answer

The Null option represents the absence of a property. For example, if you filter by Ticket group and select Null, you see all the tickets that don't belong to any group.

The Null option is by default a part of every filter you add to a dashboard. This doesn't necessarily mean it's applicable to every filter. Sometimes it isn't useful and doesn't apply to the filter at all. For example, in the Voice Default Dashboard, when you filter by Call Voice number the Null option appears, even though a Voice number naturally associates with all Voice calls.

Whether the Null option is relevant or not depends entirely on what that filter filters. See the metrics and attributes references to find how Analytics bases and calculates the filter.