I meant to post this last week already but oh well…
That’s precisely the issue. Where does it say Korean (Kore) shouldn’t be used or that Hangul (Hang) should be preferred? Unlike Japanese and some other languages there is no guideline.
To properly use the release script field we would need to understand it first.
The script list in MBS seems based on ISO 15924 which also includes special codes such as:
Common (Zyyy) or Inherited (Zinh)
Those are for Unicode. So that bears the question what the purpose of release script is and how they are related:
https://www.unicode.org/reports/tr24/#Relation_To_ISO15924
In some cases the match between the Script property values and the ISO 15924 codes is not precise, because the goals are somewhat different. ISO 15924 is aimed primarily at the bibliographic identification of scripts; consequently, it occasionally identifies varieties of scripts that may be useful for book cataloging, but that are not considered distinct scripts in the Unicode Standard. For example, ISO 15924 has separate script codes for the Fraktur and Gaelic varieties of the Latin script.
Take mathematical notation (Zmth) or symbols (Zsym) for example.
https://en.wikipedia.org/wiki/Script_(Unicode)#List_of_scripts_in_Unicode
Not used are, among others, the ISO 15924 script codes: Zsym (Symbols) and Zmth (Mathematical notation). These are considered not to be scripts in Unicode sense.
These are present and used in MB. Emoji releases exist but no emoji script (Zsye)
Morse code (MBS-11876) releases exist but no script.
What’s MusicBrainz’ standard for script? It includes scripts for which Unicode has no script yet lacks many scripts for which ISO codes exist.
[multiple scripts] being an oddball as MBS uses the private code Qaaa (which is reserved and therefore not safe for use)
Zsye and Zsym also being special as can be used for controlling presentation of emoji
Let’s look at BCP 47:
https://scriptsource.org/cms/scripts/page.php?item_id=language_detail&key=kor
The paring of Korean (kor) to Korean script (Kore) seems quite clear there.
CSS Text Module points towards assuming Kore for Korean language.
However, BCP47 script subtags are not typically used (and are in fact discouraged) for languages strongly associated with a single writing system: instead that writing system is expected to be implied when no other is specified. [BCP47] IANA maintains a database of various languages’ most common writing system via the Suppress-Script field in its language subtag registry for this purpose.
https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
Type: language
Subtag: ko
Description: Korean
Added: 2005-10-16
Suppress-Script: Kore
Japanese language/script guidelines already seem to follow this practice where you normally use/assume Jpan script for Japanese language unless there is a need to use a different script such Latn for transliterated tracklists.
Analogously I’d expect Korean language tracklists would normally use Kore script.
Or maybe we should just get rid of the script field while at it:
(Note, I didn’t know anything about this before and just researched it so might be interpreting some things wrong)