BS 7666 Spatial datasets for geographical referencing is undergoing revision, under the auspices of BSI committee IST/36 Geographic information. This revision incorporates changes suggestions made over the past few years.
The revised Part 1 Specification for a street gazetteer was published in December 2019
The revised Part 2 Specification for a land and property gazetteer is out for public comment until 19th August 2020: https://standardsdevelopment.bsigroup.com/projects/2020-00294#/section
The general model in Part 0 may well be revised after this.
A short presentation has been prepared to give an overview of the review process, which you can either view or download from here:
Further information on BS 7666 can be found on the BS 7666 Guidelines page http://www.agi.org.uk/agi-group/standards-committee/bs7666-guidelines