There are misprints in postgres doc., in :

Chapter 10. PL/pgSQL - SQL Procedural Language (c40914117.htm)

Statements
...
(resulting in a PL/pgSQL internal SELECT).
But there are cases where someone isn't interested int
-----------------------------------------(have to be)-->
But there are cases where someone isn't interested in
     the functions result.

 RAISE level format''
--(have to be)-->
 RAISE level 'format'