Restrict "Move to HR" Until DOB is Filled by HR - Fast Formula

Does this formula for restricting "Move to HR" Until DOB is Filled by HR work for anyone?

/***** Fast Formula: Prevent Move to HR if HR has not entered Date of Birth *****/

DEFAULT_FOR HR_DOB IS NULL /* Replace with the actual field name */

IF (HR_DOB IS NULL) THEN
RETURN 'ERROR: HR must enter Date of Birth before moving the candidate to HR.'
ENDIF