How to Delete a Position from a Zone
Login to Ad Manager. Scroll down to the bottom of the page and click on:
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Click Zone Configuration on the next page:
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Make sure you're in the right web property. If you're not, just click on the drop-down menu and select the property you wish to work on:
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To delete a position, go to that position and click the trashcan icon:
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A warning message will appear:
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Click okay to remove the zone.