Request for IMM5476 -Representative form for Principal applicant

[nick1899]

Experts,
My wife and I have applied for PR, I am the principal applicant. Today, I got a request for submitting additional documents- IMM5476 form.
I am confused now, if I am my own representative then why do I need to fill this form. Or do i put my wife' details but the letter is addressed to me.

Please advice.

Thanks!