ISBN gets changed when I submit my listing

[heatemyfather]

In the ISBN box I have entered the 10-digit ISBN number from the book I am listing, however I notice when I view the listing it's been changed with additional digits. Is the box title misleading/incorrect? There is a barcode on the book as well, but that is not the ISBN. When I enter the barcode it doesn't get changed.

[tony41]

Don't know if this is relevant. ISBN numbers used to have 10 digits. This was changed to 13 digits. For a while both ISBN number were given in books. Is it possible that youe 10 digit number is being automatically converted to the equivalent 13 digit numbers?

[heatemyfather]

Don't know if this is relevant. ISBN numbers used to have 10 digits. This was changed to 13 digits. For a while both ISBN number were given in books. Is it possible that youe 10 digit number is being automatically converted to the equivalent 13 digit numbers?

It's possible, but I don't see how that would help when the book has a 10-digit ISBN and probably never had a 13-digit one as it's long out of print.