A hub wide tag filter allows a hub owner to apply transformations to the tags on all items in this hub. A filter can be used to:
  • Add a tag to all items,
  • Remove a tag from all items, and
  • Modify a tag.
Filters can also be applied at the input source and feed item levels. The tags on a feed item have had tag filters applied to them in this order:
  1. Hub-wide tag filters first,
  2. then the input source tag filters, and finally
  3. the item-level filters.
This allows the effects of a filter to "cascade" down, and a hub-wide tag filter can easily be overridden at the input source or feed item levels.