Types of RTB ad blocks
Yandex Advertising Network offers website owners a wide range of formats and options for configuring ad blocks.
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 media 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 Yandex Advertising Network, use an adaptive block or flexible blocks with fixed size container boundaries (vertical or horizontal).