As far as I'm aware it's a +1 to my fellow 'Zed'man. I never get to see the self-assessment form myself, even my own is handled by my Accountant, I just sign whatever I'm sent!!! I'm very confident it's the 'gross' pension contribution you insert when prompted so just be careful there (the figure won't be the figure you see leaving your payslip/bank account - that would be too easy).
Current -: 370Z GT Roadster / Qashqai+2 Tekna 1.6dci
Gone -: BMW X3 3.0d xdrive M Sport; E46 330i M Sport Coupe; Mazda RX8 231; Nissan 350Z GT Roadster; BMW E90 330d M Sport; BMW E92 335i SE; Maserati 4200; Nissan 350Z; Honda S2000; Astra Coupe Turbo; Ford Probe