TYPO3: TCA make type „select“ optional with empty „option“

typo3_optional_select

'feld' => array(
    'exclude' => 0,
    'label' => 'Feld Name',
    'config' => array(
        'type' => 'select',
        'items' => Array (
                Array("",0),
            ),                
        'foreign_table' => 'tx_deinetabelle',
        'size' => 1,
        'minitems' => 0,
        'maxitems' => 1,
    ),
),