Section 21

If a question with respect to a patent or application is referred by any person to the Registrar under section 20, and is not determined before the time when the application is first in order for a grant of a patent pursuant to the application, that fact does not prevent the grant of a patent, but on its grant that person is treated as having referred to the Registrar under section 47 any question mentioned in that section which the Registrar thinks appropriate.