Dad, auntie, nana, grandpa, etc... What is this group of words used as informal family nicknames called?

When explaining to someone learning French when one has to use vous (the “formal you” pronoun) or tu (the “informal you” pronoun), there is a basic rule of thumb I find useful:

• Vous — Used when speaking to people you usually call by their last name, title, or occupation.

  for example: Ms Smith, Sir, Doctor, Officer...

• Tu — Used when speaking to people you usually call by their first name, nickname, or [? some word or phrase meaning informal/familiar family nickname ?].

  for example: Georges, G-dog, Grandpa...

I’m trying to find a word or short phrase to describe “family nicknames” like Dad, Nana, etc., preferably one that doesn’t include the more formal versions like Father, Grandmother, etc.

They are kinship terms (or kinship words).

This special class may overlap with what are known as terms of endearment: those words we use to address people for which we feel affection.