We sometimes have questions along the lines of when did a certain edition of IEE Regs. come into effect. The relatively recent 15th and 16th editions are fairly well known, but earlier issue dates are not so widely known.
I've posted a list in the Technical Reference area which shows all issue dates from 1882 through to the first metric edition in 1970. U.K. - Old IEE Wiring Regs. Issue Dates