EXAMPLE: WHS 04550

W = INTERNAL REFERENCE
H = MONTH 
S = YEAR 

MONTH	YEAR
A = JANUARY	N = 2021
B = FEBRUARY	O = 2022
C = MARCH	P = 2023
D = APRIL	R = 2024
E = MAY	S = 2025
F = JUNE	T = 2026
G = JULY	U = 2027
H = AUGUST	V = 2028
I = SEPTEMBER	W = 2029
J = OCTOBER	X = 2030
K = NOVEMBER	Y = 2031
L = DECEMBER	Z = 2032

Note: The letter "Q" was skipped for year since it may look like "O".