If it's cables are run through walls without adequate mechanical protection i.e. to switches surely it's code 2 if there's no RCD and the conditions of reg 522.6.6/OSG 7.3.2 aren't met
The esc recomendation for the above is code 4
The original question I would say code 4 as well
Maybe the lighting is surface clipped or trunked and we are all wrong