What does ISBN stand for?

• A. International Standard Book Number for identification
• B. Internet Standard Book Number
• C. International System for Books and Notation
• D. International Standard Bookmark Number

Answer: (A)

This question tests whether you know what the acronym stands for and what the code does. An ISBN is an International Standard Book Number, a unique numeric identifier assigned to a specific edition and format of a book. It helps publishers, booksellers, libraries, and distributors track titles and editions accurately, preventing mix-ups between similar books.

Historically ISBNs were 10 digits, and since 2007 they’re typically 13 digits, often matching the barcode used on shelves. The 13-digit form starts with 978 or 979 and includes a final check digit to verify accuracy.

Other phrases like Internet Standard Book Number, International System for Books and Notation, or International Standard Bookmark Number don’t correspond to a real, recognized identifier for books, which is why they aren’t correct.