ICU database?

I'm creating a PG cluster with Swiss High German ICU locales.

I wonder why "collate = C" and "ctype = C" is shown?

initdb --locale-provider=icu --icu-locale=de-CH-x-icu -D /path/to/datainitdb

CREATE DATABASE eng001

WITH

OWNER = dbowner

ENCODING = 'UTF8'

LOCALE_PROVIDER = 'icu'

ICU_LOCALE = 'de-CH-x-icu'

;

postgres=# \l

List of databases

Name | Owner | Encoding | Locale Provider | Collate | Ctype | Locale | ICU Rules | Access privileges

-----------+----------+----------+-----------------+---------+-------+-------------+-----------+-----------------------

eng001 | dbowner | UTF8 | icu | C | C | de-CH-x-icu | | =CTc/dbowner +

| | | | | | | | dbowner=CTc/dbowner

postgres | postgres | UTF8 | icu | C | C | de-CH-x-icu | |

template0 | postgres | UTF8 | icu | C | C | de-CH-x-icu | | =c/postgres +

| | | | | | | | postgres=CTc/postgres

template1 | postgres | UTF8 | icu | C | C | de-CH-x-icu | | =c/postgres +

| | | | | | | | postgres=CTc/postgres

(4 rows)