What you are saying is correct. In this case I would have the join of t3 on the same indent level as the join of t2 as t3 table has also the common key with t1.

What you are saying is correct. In this case I would have the join of t3 on the same indent level as the join of t2 as t3 table has also the common key with t1. Somehow I just find the parent comment style not so intuitive for me.