An ad format is a web page branding with one, 2 or 3 panels - top, left, right. Branding panels are html files. On click or mouseover the fullscreen panel appears. Fullscreen panel closes by clicking the Close button in the top right corner. Multipanel branding may contain different target URLs for each panel.
Branding: width and height depend on a web page layout. Make sure that the banner content (top, left and right sides) is aligned as close to the website as possible, so it is visible on most screen resolutions. The website background color should be considered on the borders of the banner-to-website background transition.