The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/16/plpgsql-errors-and-messages.html Description:
The using option is documented as follows for all variants of the raise statement: USING option = expression [, ... ] However, since "do $$ begin raise notice using message := 'foo'; end $$;" works and the alternative to "=" is documented in https://www.postgresql.org/docs/current/plpgsql-statements.html#PLPGSQL-STATEMENTS-ASSIGNMENT I suggest to change the grammar to USING option { := | = } expression [, ... ] for the raise statement.