The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/sql-createfunction.html
Description:
the documentation for creating a function shows [ RETURNS rettype | RETURNS
TABLE ( column_name column_type [, ...] ) ] but returns is not optional. At
least when specifying LANGUAGE plpgsql. All the online advice suggests
specifying RETURNS void as the solution.