This section is regarding to family class sponsorship.
It's rare that there will be "non-accompanying family members" that needs to fill military service forms.
e.g. spouse being sponsored by PR/Canadian, their dependents would be children under 22 years old.
Is that your question?
Spouse/common law partner and children under 22 years of age are considered family members.
You need to tell us who the primary applicant is and what their relationship is to the non-accompanying family member. Until you tell us that, we cannot help you.