API 650 Material Grouping Table 4.4a

[JXWu]

In Table 4.4a, A36M is grouped under I and II.
Note 3 for Group I A36M says "Thickness ≤ 20 mm."
Note 5 for Group II A36M says "...... Thicknesses ≤ 20 mm shall have a manganese content of 0.80 % to 1.20 % by heat analysis.

My question is; does the requirement in note 5 applies to note 3 if my material thickness is 18 mm for example?
Per ASTM A36M, plate less than 20 mm does not have limitation for Manganese.

Thanks.