From Halopedia, the Halo wiki
Featured video is a community feature to present video trailers, documentaries and the like on the main page.
Featured video is limited to videos accessible via video-sharing sites YouTube (preferably) and Vimeo (where available as an alternative to YouTube). Videos that win voting will be put on the featured article template.
To view the featured video harness go here.
How to nominate
To make a nominate, simply post the video URL in this nomination page. An administrator will assess the video and add it to the featured video list if the video is related to Halo (in-universe or out-universe) and is uploaded by a reputable channel/author/producer.