I found answer on https://www.unicode.org/reports/tr35/tr35-collation.html
and https://cldr.unicode.org/index/bcp47-extension
On Wed, May 25, 2022 at 1:52 PM jian he wrote:
>
> code from
> https://www.postgresql.org/message-id/flat/5e756dd6-0e91-d778-96fd-b1bcb06c161a%402ndquadrant.com
>
>> DRO
jian he wrote:
> So which website can I get the info about the "kf" and "u".
https://unicode.org/reports/tr35/#u_Extension
https://www.unicode.org/reports/tr35/tr35-collation.html#Collation_Settings
Best regards,
--
Daniel Vérité
https://postgresql.verite.pro/
Twitter: @DanielVerite
code from
https://www.postgresql.org/message-id/flat/5e756dd6-0e91-d778-96fd-b1bcb06c161a%402ndquadrant.com
> DROP DATABASE IF EXISTS dbicu;
> CREATE DATABASE dbicu LOCALE_PROVIDER icu LOCALE 'en_US' ICU_LOCALE
> 'en-u-kf-upper' template 'template0';
> \c dbicu
> CREATE COLLATION upperfirst (provi