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/2018/national-specific-templates-log-files-ss

Related links

Reporting
PS16/18 - Changes in insurance reporting requirements https://www.bankofengland.co.uk/prudential-regulation/publication/2018/changes-in-insurance-reporting-requirements