'{pm_block_user} holds data mapping which authors who cannot messages to which recipients ', 'fields' => array( 'author' => array( 'description' => 'ID of the author', 'type' => 'int', 'not null' => TRUE, 'unsigned' => TRUE, ), 'recipient' => array( 'description' => 'ID of the recipient', 'type' => 'int', 'not null' => TRUE, 'unsigned' => TRUE, ), ), 'primary key' => array('author', 'recipient'), ); return $schema; }