Types of RTB ad blocks
Yandex Advertising Network offers a wide range of formats and ad block design customizations for website owners.
RTB blocks can display both Yandex.Direct contextual ads (including those with mobile app advertising) and media banners, including smart banners. Partners can select several multimedia ad formats to be displayed in the block. Using this system, the block size can change from one impression to the next.
If you want to use a format which is not available in the Advertising Network, use the adaptive block or unfixed blocks with fixed size container boundaries (vertical or horizontal).