Flesh out grammatical categories

[macchiati]

We have a set of grammatical categories/features in CLDR, that are also used in ICU. It would be very useful to flesh out these categories so that we have a consistent set of identifiers for grammatical categories, and lists of which categories are applicable to which languages, and for which scopes.

Currently the data for this is limited:

1. Nouns & noun clauses: gender, case, definiteness, plurals (cardinals), ordinals, plural ranges.
2. Two scopes: general and units
3. Limited locales
   1. gender, case, definiteness: (50) Amharic, Arabic, Armenian, Azerbaijani, Bangla, ... Turkish, Ukrainian, Urdu, Uzbek
   2. plurals: (300+) Afrikaans, Akan, Albanian, Amharic, Anii, Arabic, Aragonese, Armenian, Assamese, Asturian, Asu, Azerbaijani, ... Xhosa, Yakut, Yiddish, Yoruba, Zulu

https://www.unicode.org/cldr/charts/45/grammar/index.html

• https://github.com/unicode-org/cldr/blob/main/common/supplemental/grammaticalFeatures.xml

https://www.unicode.org/cldr/charts/45/supplemental/language_plural_rules.html

• https://github.com/unicode-org/cldr/blob/main/common/supplemental/plurals.xml
• https://github.com/unicode-org/cldr/blob/main/common/supplemental/ordinals.xml
• https://github.com/unicode-org/cldr/blob/main/common/supplemental/pluralRanges.xml

[nciric]

I think this would be beneficial to CLDR/ICU with improving data quality and maybe reducing the size. It could also help our effort in defining which categories we want to tackle.