BUG #16997: parameter server_encoding's category problem

The following bug has been logged on the website:

Bug reference:      16997
Logged by:          yanliang lei
Email address:      leiyanliang@highgo.com
PostgreSQL version: 13.1
Operating system:   CentOS7.6
Description:

In the following sql statement， parameter server_encoding's category is
“Client Connection Defaults / Locale and Formatting”：

postgres=# select category from pg_settings where name='server_encoding';
-[ RECORD 1 ]------------------------------------------------
category | Client Connection Defaults / Locale and Formatting

postgres=# 

In the document
https://www.postgresql.org/docs/current/runtime-config-client.html#RUNTIME-CONFIG-CLIENT-FORMAT，
there is no entry about parameter server_encoding.

and in the document
https://www.postgresql.org/docs/current/runtime-config-preset.html,there is
a entry about parameter server_encoding.

so, What is the parameter server_encoding's category?