No, there is essentially no difference. Protective Multiple Earthing (PME) is the method used by the DNO to earth their low voltage network supplying a TN-C-S Installation, via a system of distributed earth electrodes along the Protective Earth Neutral (PEN) conductor. See BS7671:2008 Amt 1, Definitions, Protective Multiple Earthing (page 32) and Figure 3.9 (page 44)
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