Tax refunded in the year

I am self employed and filling in box w85 of the tax calculation guide (or
box 20.1 from main tax form). It wants my tax refunded in the year. I
received a payment of £xxx. But in a letter regarding this, it says "This
includes Repayment Supplement arising and already present of £xx.

What is Repayment Supplement and do I include the replayment supplement or
deduct it?

e.g. repayment total: £1000 repayment supplement: £150. I put £1000 or £850
into the box?

Thanks,

Jon


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