The Fertilisers Regulations 1990

6.  The content declared in accordance with paragraph 1(d) shall be indicated both in words and by the appropriate chemical symbol as follows:—

(a)Nitrogen (N);

(b)Phosphorus pentoxide (P2O5);

(c)Potassium oxide (K2O);

(d)Magnesium oxide (MgO);

(e)Chlorine (Cl).