What is the intent of Box 18 on a T4RIF?

The form says it is "Amounts deemed received by the annuitant - Deceased". I don't recall my father in law's estate receiving anything like that amount from this company.

After you file

Box 18 of T4RIF - Deemed received (by the annuitant) on death. This is the fair market value of all the property held by the RRIF at the time of the annuitant's death. 

Learn more from the links below.

If you are uncertain of the amount applied to this box, you may want to contact the issuer of the T4RIF to get a clearer explanation.