Always use official sources when they are available.
The first search result is often not the official trailer. Take some time to browse further and you will eventually find something official.
To find out what is official, check the names of the productions companies and/or distributors for a movie (IMDb listings can be very helpful here).
It's also common for official videos to be part of a specific movie channel on YouTube (e.g 3 Days to Kill) or even a specific franchise channel (e.g. Need for Speed, both video games and movie stuff in one channel).
In rare cases, the trailer can be added by a person connected to the movie (actor, producer, director, etc).
If there are no official sources, semi-official channels such as the Fandango channels can be used.
Always use the original trailer if possible. Avoid using trailers with intros or outros created by the uploader.
Fan-made trailers are NOT allowed.
YouTube videos that have no region restrictions are preferable. Tools like this one will help identify them.
Official videos are not spoiler-free. If you don't want to see spoilers, do not watch the videos. ;D
Full movies are not allowed.
Deleting good official videos will result in a warning or ban.
Malicious edits will result in a ban.
YouTube videos are country/language specific, e.g. you have to select "Danish (da-DK)" to add a Danish video.
The language of a video is usually determined by the main language spoken in the video. e.g. the trailer for a Hindi movie with a romanized title and an English description should be added to Hindi (hi-IN) if the trailer is in Hindi
Subtitles: A video with English audio and subtitled in French should be added as a French video. In contrast, a video with French audio but subtitled in English should be added as an English video.
Teaser trailers are usually added as trailers, not teasers, with the exception for teaser trailers shorter than 75 seconds.
Teasers are shorter than trailers (and will typically have "teaser" in the title).
A trailer tease should—of course—be added as a teaser. It's usually a few seconds of footage promoting the upcoming trailer.
TV commercials—preferably added as "TV Spots"—are usually added as teasers.
Any scene from a movie—usually listed as a Clip—should be added as a clip.
Any material that is not a trailer, a teaser (including TV Spots) or a clip, should be added as a featurette. This include BTS interviews and footage (e.g. "Behind the Bricks" Featurette).
Please select the right one: Standard (360p or less), HQ (480p), HD (720p), HD (1080p and more)
The quality can be found by clicking on the little wheel located at the bottom right corner of each YouTube video. We want the maximum resolution available for the video.
The source key is a series of eleven numbers, letters, underscores and hyphens that can be found in the URL of a video directly after "watch?v=" e.g. "INLzqh7rZ-U" from this URL: https://www.youtube.com/watch?v=INLzqh7rZ-U
You can simply copy and paste the complete YouTube URL into the source key input. We'll automatically parse the YouTube ID.
No embed codes!
When adding a name for a video, do not copy the long YouTube title. Always edit out the movie title and unnecessary info. e.g. "T2 TRAINSPOTTING - Official Trailer (HD)" should be added as "Official Trailer"
When a movie has two or more trailers, the official sources usually use numbers to differentiate the trailers. e.g. "Sing - In Theaters This Christmas - Official Trailer (HD)" should be added as "Official Trailer" and "Sing - In Theaters This Christmas - Official Trailer #2 (HD)" as "Official Trailer #2"
When the first trailer is titled "Official Trailer", you can add it like that (no need to add a 1). But when an official trailer is titled "Trailer 1", feel free to add it as "Official Trailer 1".
Subtitled trailers should be marked as such. This is often the case for non-English movies released in the US. Many countries (e.g. France) release two versions of the same trailer: an original subtitled version (e.g. "Bande Annonce Officielle (VOST)") and a dubbed version (e.g. "Bande Annonce Officielle (VF)").