Some of the Arcadia artwork contains a numeric substitution cipher which can be decoded to spell out certain words and phrases. When alternative artwork was used outside of the UK, some countries used randomised numbers which don't spell out anything intelligible.
Cracking The Number Code

00 = SPACE
02 = T
04 = U
06 = V
08 = W
10 = X
12 = Y
14 = Z
16 = A 18 = B
20 = C
22 = D
24 = E
26 = F
28 = G
30 = H
32 = I
34 = J 36 = K
38 = L
40 = M
42 = N
44 = O
46 = P
48 = Q
50 = R
52 = S