Ad units inherit settings, such as target window, from their parent ad unit or network defaults.
The icon indicates that the value for the setting is aligned with the parent or the network default. An orange inherited icon indicates that the value has been overridden and is no longer aligned with the parent or the network default.
A Clear override option appears next to settings that have been overridden. This option won't appear if the setting is not overridden. To revert a settings to the inherited value, click Clear override option. Whenever a setting is aligned with the parent or the network default, the "Override" icon is grey.
Top-level versus child ad units and overrides
Only top-level ad units inherit settings from your network defaults. Child ad units inherit their settings from parent ad units.
Top-level ad units are considered overridden when they vary from the network defaults. Child ad unit settings are not considered overridden if they vary from network defaults.
Child ad units inherit the setting of their parent, and these settings are considered overridden only if they vary from their parent settings. If the child ad unit's setting is aligned with its parent, no override is indicated—the "Override" icon is grey. If the setting varies from its parent, the "Override" icon is orange.