11. Where an entitled officer who is in receipt of an annual allowance under regulation 4 enters or continues in employment which would constitute NHS employment for the purposes of regulation S2 of the Superannuation Scheme Regulations (reduction of pension on return to NHS employment), the annual rate of that allowance together with any pension payable under those Regulations shall not exceed the rate at which the compensation would have been paid if the aggregate of the allowance and pension had been a pension liable to reduction under the said regulation S2.