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/*-----------------------------------------------------------------------------------*/
/*	WooCommerce - Change Checkout Notes Label and Place Holder Text
/*-----------------------------------------------------------------------------------*/

// Hook in
add_filter( 'woocommerce_checkout_fields' , 'theme_override_checkout_notes_fields' );

// Our hooked in function - $fields is passed via the filter!
function theme_override_checkout_notes_fields( $fields ) {
     $fields['order']['order_comments']['placeholder'] = 'Add some order notes or a gift message here.';
     $fields['order']['order_comments']['label'] = 'Order notes or  gift message';
     return $fields;
}