Review of additional documents - not applicable

My AOR date - 27 August 2019 Med passed - 12 sept 2019 Received biometrics letter on same date and submitted it on 18th sept 2019 11 december - request for additional document i.e. Additiomal family information form (IMM 5406) Submitted it on 12th december. The status of Review od Additional documents changed to “Not Applicable”. Does any body have idea what "Not Applicable " means?

Hi… Any idea?