Song legality

The idea of what constitutes a "song" is somewhat subjective and open to interpretation. However, for the purposes of this project songs are considered pieces of music with vocals, to distinguish them from original soundtracks (OST).

OSTs will never be legal for a myriad of practical and philosophical reasons.

All songs

 * The minimum duration for any given song is.
 * A song must actually appear in an entry to be legal.
 * A song must be credited for it to be legal.
 * At minimum, a song needs the following information available:
 * Song title
 * Song artist/performer
 * Approved entry in MAL
 * Songs that fail to meet any of these requirements are banned, even if they satisfy other requirements.
 * Database moderators ultimately have discretion over what is constituted as legal or not.
 * Do not use existing exceptions to justify adding a song that has been banned or rejected.

Openings (OP) and Endings (ED)

 * 1) Songs that appear in more than one episode are legal.
 * 2) Songs that appear for less than the minimum duration of  may be allowed as an OP/ED.
 * 3) Songs that appear in a single episode and are credited are legal.
 * 4) Instrumental songs are allowed as an OP/ED as long as they are credited.
 * 5) Uncredited instrumentals are banned as they are too close to OST.

Movies and other single episode entries
TBD but mostly the same rules as above

Inserts (IN)

 * 1) Instrumental INs are banned, regardless of whether they are credited.
 * 2) There is no special consideration for "major pieces"
 * 3) * e.g. Shigatsu wa Kimi no Uso, Hibike! Euphonium performances are banned.
 * 4) See discussion at the top of this page regarding vocals and OSTs.
 * 5) Songs that do not appear clean in the entry and do not have clean releases available are banned.
 * 6) * Examples:
 * 7) ** A song plays mostly clean in the entry: Legal
 * 8) ** A song plays unclean with dialogue and/or sound effects over it in the entry, but a clean CD release is available: Legal
 * 9) ** A song plays unclean with dialogue and/or sound effects over it in the entry, and has no available clean release: Banned

Cameo appearances

 * 1) A cameo appearance of a song in another entry besides the original entry is legal, as long as it meets the other requirements.
 * 2) A cameo appearance of a song may be legal even if it isn't officially credited by the entry.
 * 3) This is an exception and does not apply universally.

Theme

 * A song that plays throughout an entire work, e.g. for an MV.
 * Considering merging this into Inserts and tagging it with a "Theme" tag.

Categorization priority

 * 1) Songs will not be linked to the same entry more than once.
 * 2) Songs that appear both as an OP and an ED in the same entry are categorized according to the first applicable:
 * 3) Most frequent appearance type
 * 4) First appearance, if above is tied
 * 5) Longest appearance, if above is tied
 * 6) OP over ED
 * 7) A song linked as an OP can't be linked as an ED in the same entry, and vice versa.
 * 8) A song linked as an OP or ED can't be linked as an IN in the same entry.
 * 9) * OP/ED always take priority over IN
 * 10) * This does not apply to distinct versions of songs, e.g. a special ED version with a different artist.