As concerns the Porsche 911, there are 3 types of chassis number; they allow to know the age of built, the version (Coupè, Targa, Cabriolet), the model (911, 911 turbo), the displacement, the power, and the number of models which have been builted.

 

1964-1968

The chassis number is formed with 8 ciphers:

1 1 8 3 0 0 0 1
11 signifies 911.
Age of built.
Kind of body.
Ascending number.

 

1969 - 1981

The chassis number is formed with 9 ciphers:

9 1 1 8 3 1 1 1 0 0
They're the ciphers of the model. 911=911, 930= 911 Turbo.
Age of built.
Model: 6=Carrera, 3=SC.
Body: 0=Coupè, 1=Targa or Cabrio.
Ascending number.

 

1980

There's a letter after the 2nd cipher but it's a temporary moment:

91A 0 1 3 0001

 

FROM 1981

Here's the numeration which is used nowadays:

WPO ZZZ 91 Z B S 1 0 00001
Not particoular significance.
Not particoular significance.
The first two ciphers of the model: 91= 911, 93=Turbo, 96= 964, 99=993 o 996.
Not particoular significance.
Age of built; A=1981, B=1982 ecc.
Production place: S=Stuttgart, N=Neckarsulm.
Third ciphers which allows to identify the model.
Body or engine type.
Ascending number.

 

Here are all the chassis numbers of the 911s ever builted:
1 9 6 4
1 9 6 5

1 9 6 6
1 9 6 7
1 9 6 8
1 9 6 9
1 9 7 0
1 9 7 1
1 9 7 2
1 9 7 3
1 9 7 4
1 9 7 5
1 9 7 6
1 9 7 7
1 9 7 8
1 9 7 9
1 9 8 0
1 9 8 1
1 9 8 2
1 9 8 3
1 9 8 4
1 9 8 5
1 9 8 6
1 9 8 7
1 9 8 8
1 9 8 9
1 9 9 0
1 9 9 1
1 9 9 2
1 9 9 3
1 9 9 4
1 9 9 5
1 9 9 6
1 9 9 7
1 9 9 8
1 9 9 9