The format of the ISWN or ISWN-B is a string of 23 characters.

It is a concatenation of subcodes, each representing a key characteristic of a bottle of wine:

XXX	-	XX	-	XX.XXX	-	XXX	/	XXXX	-	XXXX	-	X	/	X
123	-	45	-	67.890	-	123	/	4567	-	8901	-	2	/	3

Click on any of the subcodes below to get more information, or look at the example.

country CCC -	region RR -	producer PP.PPP -	wine WWW /	vintage YYYY -	volume VVVV -	special B / X
<----------------- ISWN-P ----------------->
<------------------------- ISWN-W ------------------------>
<--------------------------------- ISWN-V ---------------------------------->
<----------------------------------------- ISWN-B ----------------------------------------->

From ISWN #71009002180011996007500, we can derive this: it is a standard 75 ml bottle of South African Cabernet Sauvignon by Thelema Winery, 1996 vintage.
 

The ISWN is composed as:

710 - 09 - 00.218 - 001 / 1996 - 0075 - 0 / 0 CCC - RR - PP.PPP - WWW / YYYY - VVVV - B / X

and reads as follows:

ISWN-P ISWN-W ISWN-V ISWN-B

710 710 710 710 710 710

- 09 - 09 - 09 - 09 - 09

- 00.218 - 00.218 - 00.218 - 00.218

- 001 - 001 - 001

/ 1996 / 1996

- 0075

is South Africa  is regio Stellenbosch  is Thelema Winery  is Thelema's Cabernet Sauvignon  is the 1996 vintage of this wine  is a 75 ml bottle