Roman numerals

Just noticed that the BBC uses Roman numerals for copyright dating. (c) MMVIII.

I - 1
V - 5
X - 10
L - 50
C - 100
D - 500
M - 1000

1 I
2 II
3 III
4 IV
5 V
6 VI
7 VII
8 VIII
9 IX
10 X
11 XI
12 XII
13 XIII
14 XIV
15 XV
16 XVI
17 XVII
18 XVIII
19 XIX
20 XX