New property TCEFORM.<table>.<field>.keepItems keeps declared items in the select box, while removing everything else. It should be used in PageTS. For example:
TCEFORM.pages.doktype {
keepItems = 1,2,255
}
More info:
RFC: Feature Request #5610: Extend TCEFORM_confObj on Page TSconfig by property keepItems
http://bugs.typo3.org/view.php?id=5610