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 (provider = icu, locale = 'en-u-kf-upper'); > CREATE TABLE icu(def text, en text COLLATE "en_US", upfirst text COLLATE > upperfirst); > INSERT INTO icu VALUES ('a', 'a', 'a'), ('b','b','b'), ('A','A','A'), > ('B','B','B'); > SELECT def AS def FROM icu ORDER BY def; > SELECT def AS en FROM icu ORDER BY en; > SELECT def AS upfirst FROM icu ORDER BY upfirst; > SELECT def AS upfirst_explicit FROM icu ORDER BY en COLLATE upperfirst; > SELECT def AS en_x_explicit FROM icu ORDER BY def COLLATE "en-x-icu"; > - trying to replicate the above quoted command. - So I don't know * ICU_LOCALE 'en-u-kf-upper' *the *u *and the *kf *refer to? Even I followed https://unicode-org.github.io/icu/userguide/locale/#the-locale-concept 1. Language code 2. Script code 3. Country code 4. Variant code 5. Keywords So which website can I get the info about the "kf" and "u". -- I recommend David Deutsch's <<The Beginning of Infinity>> Jian