The ISO standard VIN

Vehicle identification number

A Vehicle Identification Number, commonly abbreviated to VIN, is a unique serial number used by the automotive industry to identify individual motor vehicles. VINs were first used in 1954...

 was introduced for the Porsche

Porsche

Porsche Automobil Holding SE, usually shortened to Porsche SE a Societas Europaea or European Public Company, is a German based holding company with investments in the automotive industry....

 model year 1981.

VINs consist of 17 characters and for Porsche can be decoded as follows:-

Position	Explanation
1	W = German based manufacturer.
2	P = Porsche.
3	0 (zero) = Passenger car (applies to all except Cayenne) or 1 = SUV (applies to Cayenne).
4	for RoW = Z (filler)	for USA etc = The Vehicle Specification (read positions 4,5 and 6 together).
5	for RoW = Z (filler)	for USA etc = The Vehicle Specification (read positions 4,5 and 6 together).
6	for RoW = Z (filler)	for USA etc = The Vehicle Specification (read positions 4,5 and 6 together).
7	First character of model type (read positions 7,8 and 12 together).
8	Second character of model type (read positions 7,8 and 12 together).
9	For RoW = Z (filler)	for USA etc = calculated checkdigit.
10	Year code.
11	Factory code.
12	Third character of model type (read positions 7,8 and 12 together).
13	Body configuration code.
14	First digit of serial number.
15	Second digit of serial number.
16	Third digit of serial number.
17	Fourth digit of serial number.

Vehicle Specification for USA etc (positions 4,5 and 6)

VIN has been implemented differently in two regions, they consist of the following countries:-

USA etc = USA, Canada, Mexico, Japan and Switzerland.

RoW = Rest of world. (ie everywhere except USA, Canada, Mexico, Japan and Switzerland.)

Vehicle Specification for "USA etc" is a 3 character code giving details of the body type, engine, seatbelts and airbags fitted.

(More info needed.)

Examples of Model Type codes (positions 7,8 and 12)

Cayenne = 9PA.

Panamera = 970.

Boxster = 986 then 987.

Cayman = 987.

Carrera GT = 980.

911 = 964, 993, 996, 997.

928 = 928.

944 = 944.

944 Turbo = 951.

924 = 924.

924 Turbo = 931.

Year Codes (position 10)

Code	Year	---	Code	Year	---	Code	Year	---	Code	Year
			L	1990		Y	2000		A	2010
B	1981		M	1991		1	2001		B	2011
C	1982		N	1992		2	2002		C	2012
D	1983		P	1993		3	2003		D	2013
E	1984		R	1994		4	2004
F	1985		S	1995		5	2005
G	1986		T	1996		6	2006
H	1987		V	1997		7	2007
J	1988		W	1998		8	2008
K	1989		X	1999		9	2009

Factory Codes (position 11)

Code	Factory	Notes	Models Produced
S	(Stuttgart) Zuffenhausen - Germany	Includes occasional production from Weissach.	All 911s. Minority of 986 Boxsters and 987 Boxster/Cayman. Minority of 944s. Majority of 968s.
N	Neckarsulm - Germany.	Audi Audi Audi AG is a German automobile manufacturer, from supermini to crossover SUVs in various body styles and price ranges that are marketed under the Audi brand , positioned as the premium brand within the Volkswagen Group....  factory.	Majority of 924 and 944s. Minority of 968s.
L	Leipzig - Germany.		All Cayenne, Panamera and Carrera GT.
U	Uusikaupunki - Finland.	Valmet Automotive Valmet ' was a Finnish state-owned conglomerate. Valmet was formed in 1951, when the state of Finland decided to group their various factories working on war reparations to the Soviet Union under one company... factory.	Majority of 986 Boxsters and 987 Boxster/Cayman.

Examples:-

WP0ZZZ94ZFN40**** a 944.

WP0ZZZ98Z7U75**** a Cayman.

WP0ZZZ92ZGN40**** a 924S.

WP1ZZZ9PZ8LA7**** a Cayenne.

WP0ZZZ96ZRS81**** a 968.

WP0ZZZ99Z5S73**** a 911.

WP0ZZZ97ZAL08**** a Panamera.

WP0ZZZ98Z4L00**** a Carrera GT.

WP0ZZZ98Z8U72**** a Boxster S.

WP0ZZZ99Z5S76**** a 911 C2S Convertible.

WP0ZZZ99Z2S64**** a 911 C4 convertible.