This is from my 17th edition training manual, written by the NICEIC, and endorsed by city and guilds:
It also seems the regulation has been rewritten in the 17th edition to remove any ambiguity which was present in the 16th edition.
543.7.2.1 For a final circuit with a number of socket-outlets or connection units intended to supply two or more items of equipment, where it is known or reasonably expected that the total protective conductor current in normal service will exceed 10 mA, the circuit shall be provided with a high integrity protective conductor connection complying with the requirements of Regulation 543.7.1. The following arrangements of the final circuit are acceptable:
(i) A ring final circuit with a ring protective conductor. Spurs, if provided, require high integrity protective conductor connections complying with the requirements of Regulation 543.7.1
(ii) [relates to radial circuit(s)]
(a) [relates to radial circuit(s)]
(b) [relates to radial circuit(s)]
(c) [relates to radial circuit(s)]
(iii) [relates to radial circuit(s)]
It also seems the regulation has been rewritten in the 17th edition to remove any ambiguity which was present in the 16th edition.
543.7.2.1 For a final circuit with a number of socket-outlets or connection units intended to supply two or more items of equipment, where it is known or reasonably expected that the total protective conductor current in normal service will exceed 10 mA, the circuit shall be provided with a high integrity protective conductor connection complying with the requirements of Regulation 543.7.1. The following arrangements of the final circuit are acceptable:
(i) A ring final circuit with a ring protective conductor. Spurs, if provided, require high integrity protective conductor connections complying with the requirements of Regulation 543.7.1
(ii) [relates to radial circuit(s)]
(a) [relates to radial circuit(s)]
(b) [relates to radial circuit(s)]
(c) [relates to radial circuit(s)]
(iii) [relates to radial circuit(s)]