Syntax incorrect for psql 9.6

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/9.4/sql-reindex.html
Description:

For the REINDEX DATABASE command, the documentation suggests REINDEX
DATABASE databaseName, however my experience suggests this does not work;
the database name must be quoted:

sonarDB=# \c sonarDB;
You are now connected to database "sonarDB" as user "sonarUser".
sonarDB=# REINDEX DATABASE sonarDB;
ERROR:  can only reindex the currently open database
sonarDB=# REINDEX DATABASE "sonarDB";
REINDEX