I'm currently trying to become certified to create DoubleClick adverts, and I'm following Google's own certification program video, and it seems to contradict itself.
It states that close buttons are required for floating (interstitial) adverts, but halfway through their video the following happens:
Visible Close Buttons are NOT required for Mobile Browsers!
There is no further explanation as to why a Mobile Browser doesn't require a visible close button, and elsewhere in the video, and Google's documentation, it simply states visible close buttons ARE required:
In their documentation, it is also clearly stated:
This is stated again elsewhere in their documentation, this time clearly including "mobile browser":
What's going on?
It seems they meant "In-App" interstitial adverts when they said "Mobile Browser". You don't need to include code for a Close Button if you're building an interstitial for in-app use.