Rule 55 of The Probate and Administration Rules: Evidence as to terms, conditions and date of execution of written will

(1) Where there appears in a written will any obliteration, interlineation or other alteration which is not authenticated in the manner prescribed by section 20 of the Act or by the re- execution of the will or by the execution of a codicil, the court may require evidence to show whether the alteration was present at the time the will was executed and shall give directions as to the form in which the will is to be proved: Provided that this subrule shall not apply to any alteration which appears to the court to be of no practical importance.
(2) If from any mark on a will it appears to the court that some other document has been attached to the will, or if a will contains any reference to another document in such terms as to suggest that it ought to be incorporated in the will, the court may require the other document to be produced and may call for such evidence in regard to the attaching or incorporation of the document as it thinks fit.
(3) Where there is doubt as to the date on which a written or oral will was executed or made the court may require such evidence as it thinks necessary to establish the date.