In my university bookshop the other day, inquiring about the availability of a book for my research, I told the lady behind the counter that I had all the details of the book, and asked if she wanted the Title, Author list, Publisher, or what ?
"The ISBN number is all I need. Its the world standard ! With the ISBN number, I can locate the book on the computer and order it for you"
I handed over the sheet of paper with the details and pointed to the ISBN number.
"Oh, damn, you've got the American ISBN number, and we need the European ISBN number."