Adoptive (although not legal) family member?

[eletyl]

I am preparing an application to sponsor my parents.  I have a question about "adoptive" non-accompanying family members.

My mother was born in 1945, and her parents divorced soon after.  The man whom I consider my grandfather married my grandmother just a few years later, and raised my mom since the time she was a toddler.  He's been a father to her throughout her life, and a grandfather to me.  However, I only found out recently that he never actually legally adopted my mother.

He's not planning on ever coming to Canada, but I was wondering if I should even list him as non-accompanying?  Does he have any legal tie to me whatsoever?

Likewise, I assume I do need to include my biological grandfather (who has never really been a part of our lives).  Is that right?

Thanks!!