quit and exit commands have been added to psql starting from psql 11 through this commit df9f599bhttps://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=df9f599bc6f14307252ac75ea1dc997310da5ba6 but it is not documented in psql documentation
pgsql-docs by date:
Соглашаюсь с условиями обработки персональных данных