Quick one -on a 1771 form, who needs to sign Part 2 “Claimants Certificate” - I seem to remember that it needed to be the CO, rather counter-intuitively, but it’s been a long while since I’ve done one!
Thanks 
Part 2 is signed by the claimant in all cases
Part 3 is signed by the squadron commander unless they are the claimant in which case it is signed by OC Wing or the WExO
See ACP300, FI309, para 8a(2)
It should also not be countersigned by a family member, in this case they are forwarded to Wexo oc wing or WSO.
kfd’s “not a family member” is also usually taken to mean not someone you’re “living with”.
In my wing it can only been signed off by OC Wg / Dep OC Wg / WHQ Staff - recent change due to an approved signature list at HQAC