What is expandable creative?
A creative which expands under any action (mouse over, click, automatic) in any kind of directions, taking a lot of view space on a page. For correct execution of expandable creative, you need iFrame to be supported on a domain.

How iframe affects expandable creatives?

There are 2 types of iFrame in a render of correct creative expand - Friendly and Non-friendly. 

• Friendly - top-level page domain and domain is the same. For example, you go to getintent.com website and in HTML there is an iFrame with URL getintent.com/imp.html. In that case, an iFrame is friendly as a domain is the same.
• Non-friendly - domain differs from the top level page. For example, you go to getintent.com website and in HTML there is an iframe with URL dataserver.getintent.com/imp.html. Since getintent.com does not equal to dataserver.getintent.com, the iframe is non-friendly.

When expandable creative is showing in the non-friendly iFrame it is unable to expand it outside the browser boundaries according to its policy. But, if the iFrame domain supports the same iFrame Buster technology as an expandable creative do - it will work correctly.

Reports

• iFrame Busters - supported expandable vendors. You can use them when iFrame is not friendly in order to buy and show expandables correctly on the needed domain.
• Expand Directions - directions which are supported in the particular domain. Every particular ad placement can support several expand directions so take it into consideration once creating a WL.  Possible values are:
  LEFT, RIGHT, UP, DOWN, UP_LEFT, UP_RIGHT, DOWN_LEFT, DOWN_RIGHT, ANY_DIAGONAL, FULLSCREEN.
• iFrame State - state of the iFrame shared by SSPs.
• iFrame State (Detected) - detected and confirmed state of the iFrame by our AdServer on the impression stage. If there is any value in the iFrame state (Detected) field it is a friendly iframe.

Possible iFrame states (not detected):

• XD_IFRAME - ad markup has been loaded from a non-friendly iFrame.
• UNKNOWN - We have no info about the iFrame state.
• NO_IFRAME - There is no iFrame.
• IFRAME - ad markup has been loaded from iFrame. In case we receive this from OpenRTB partners, we are not sure whether it's friendly or not.

Content tags
In order to be able to bid on expandable inventory you should put one of the next content tags depending on your creative expand behavior:

• EXPANDABLE - rollover to expand
• EXPANDABLE_AUTO - expands automatically
• EXPANDABLE_CLICK - expands on click