Locale tags such as en, en-US, or sr-Latn.
en
en-US
sr-Latn
Default: discovered from the Compose resources directory by reading locale-only folders like values-en, values-pt-rBR, and values-b+sr+Latn. Set this when you want the list pinned by hand.
values-en
values-pt-rBR
values-b+sr+Latn