So, putting aside ESR 3.2.2, why do we give assemblies categories? Possibly because PED guideline A-39 says ‘the Directive clearly defines a category for each assembly in Article 14 paragraph 2.6 (b)’. But does Article 14 paragraph 2.6 (b) really say that? It makes no reference to an assembly having a category, referring only the highest category of equipment within the assembly. I think that Article 14 paragraph 2.6 (b) tells the manufacturer how to assess, not categorise, its assembly.