On August 6 2016 (5mnths) I was given the right to claim all benefits for my son (as well as custody). I just received the irs multiple claim letter. Do I need to worry.

With the included court order. Me becoming the primary custodian. As well as receiving all benefits. I also had a verbal agreement with his mom. that I would have him every wknd (Before the court custody order). The wknds put me over the 6 mth mark. But I would have one hell of a time proving it. With out it being from my family. 

The main point is: The order state's that I have the right to claim ALL benefits. From that point on. Does that suffice as proof. Of me having the right to claim.