Undocumented := alternative in using option of raise statement

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.