documentation bug - behave of NEW a OLD in plpgsql's triggers

Hello

one czech user reported a bug in documentation -
http://www.postgresql.org/docs/8.4/static/plpgsql-trigger.html

NEW

    Data type RECORD; variable holding the new database row for
INSERT/UPDATE operations in row-level triggers. This variable is NULL
in statement-level triggers and for DELETE operations.
OLD

    Data type RECORD; variable holding the old database row for
UPDATE/DELETE operations in row-level triggers. This variable is NULL
in statement-level triggers and for INSERT operations.

It isn't correct. NEW is not declared in DELETE trigger, OLD isn't
declared in INSERT

Regards

Pavel Stehule