RubyTran

Hi everyone, I’m preparing documents to apply visa 143 for Mum & Dad. I have some questions about signatures of 3 forms: Form 80, form 956 & form 47PA. For each form, do I need to get 2 signatures OR only need 1 signature of main applicant, don’t need dependant ??? If someone already did, please advise me. Thank you a lot !!! Cheers.