Vehicle Identification Number
(12 July 2006)

The Vehicle Identification Information can be found ...
1) frame number: on the steering casing, near and under the right clip-on
2) engine number: on the lower crankcase
3) homologation data: on the frame, again, on the same side as the frame number, on the steering down tube.

This is how you read a VIN - just in case you were desperate to know.
The example is my Tre - ZBNTB00003P100922

Character Description Example Explanation
1,2 Country Code ZB Italy
2,3 Manufacturer BN Benelli
4-8 Model TB000 Tornado
9 check digit 0 Not just any sequence of numbers will work!
10 Assembly Year 3 2003
11 Assembly Plant P Pesaro
12-17 Serial Number 100922 Frame Number

The '1' in the 100922 is a furphy. They haven't made 100,000 - they wish they had!
Also, andrew656 provided an explanation which differs slightly from that above. He broke up 4,5 as Vehicle type, 6 as Variant, 7 as Version, 8 as Year, 9 as Model, 10-12 as the Build Code 13-17 as the Frame Number.

Some country codes follow:-

Country Codes
Austria VA - VE
Australia 6A - 6W
Germany SN - ST, WA - WO
Italy ZA - ZR
Japan JA - JO
UK SA - SM
US 1A - 10, 4A - 40, 5A - 50

If you want more, visit an online VIN decoder.