4. Description (formal requirements)
If drawings are included they should first be briefly described, in a manner such as: "Figure 1 is a plan view of the transformer housing; Figure 2 is a side elevation of the housing; Figure 3 is an end elevation looking in the direction of the arrow X of Figure 2; Figure 4 is a cross-section taken through AA of Figure 1." When it is necessary to refer in the description to elements of the drawings, the name of the element should be referred to as well as its number, i.e. the reference should not be in the form: "3 is connected to 5 via 4" but, "resistor 3 is connected to capacitor 5 via switch 4".