This SS has not yet been added to the PRA Rulebook. It is available on the Bank of England website, here.

https://www.bankofengland.co.uk/prudential-regulation/publication/2013/the-basel-1-floor-ss

Related links

PS7/13 - Strengthening capital standards: implementing CRD IV, feedback and final rules https://www.bankofengland.co.uk/prudential-regulation/publication/2013/strengthening-capital-standards-implementing-crd-4