The material considered part of a work's official story, as opposed to filler, spin-offs or fan-created content. Read from the pairing, as a 2.
2Filed under 2. The Pairing takes a negotiation, and this entry is negotiates one.
Canon refers to what officially counts. In manga this usually means the creator's serialised chapters and anything they explicitly authored, with adaptations, spin-offs and supplementary material sitting outside it.
The boundary is rarely clean. Anime filler is generally not canon, but an anime-original ending occupies an awkward position, particularly when the creator was involved. Spin-offs drawn by other artists, films, light novel side stories and author interviews all sit in a grey zone.
Omake in collected volumes are usually non-canon jokes, but some authors use them to deliver genuine setting information.
Less than online argument implies. Canon disputes are mostly a fandom activity rather than a reading problem. For practical purposes, the manga as the creator published it is the story, and everything else is optional.
Every letter here carries a digit; together they make 20, which folds down to 2.
What the 2 brings is cooperation. The reference files it as a negotiation. Whatever else this entry is doing, it is doing it with the 2's search for balance between competing sides.
The vowels alone reduce to 7, the consonants to 4. Inquiry underneath, foundation on the surface. The gap between them is where the subject is most interesting.
The 2 asks you to find the second party, because there always is one. The 2 will keep a bad arrangement alive out of politeness. A number of these texts are about partnerships nobody ended in time. The other entries that reduce to 2 are collected on The Pairing.