Source

Provide the source that the work was adapted from.

The available options are: Original, Anime, Manga, Light Novel, Novel, Doujinshi, Visual Novel, Video Game, Other.

The source for the 'Ao Buta' anime

Like relations, sources will almost always all branch off of a single entry.

Source	Description
Original	The work was not adapted from any other form of media.
Anime	The work was adapted from anime.
Manga	The work was adapted from manga.
Light Novel	The work was adapted from a light novel.
Novel	The work was adapted from a novel.
Doujinshi	The work was adapted from a doujinshi.
Visual Novel	The work was adapted from a visual novel.
Video Game	The work was adapted from a video game.
Other	The work was adapted from another form of media.

Example:

The light novel Ookami to Koushinryou was the first published release of the series, so it would have the 'Original' source.

It then has both anime and manga adaptations announced. Both of these would be given the 'Light Novel' source. Any further spin-offs and similar relations would also be sourced to the light novel.