What is the “Other” Fee?

Here is an example breakdown of my Amazon Fees

Total
-$7,646.39
Prime Fulfillment Fee
-$67.52
Prime Service Fee
-$10.41
Subscription fees
-$39.99
Other
-$7,528.47

I assume part of that is the referral fee, but that should only be about $2800 (15% of sales), what is making up the other $4600? Refunded sales, Promo Rebates, FBA Fees, and cost of advertising are separate line items. I’m guessing FBA storage, but let me know if you have thoughts.