Category:Pages with ISBN errors

This category is populated by pages and templates that use ISBN and ISBNT.

In these templates, ISBN parameters are checked for invalid ISBNs as well as extraneous text such as "ISBN", "N/A", "none", dashes (use hyphens instead), lower-case "x" (use "X" instead), and tab characters.

Error messages for erroneous ISBNs look like one of: 1=

Check  value

Invalid ISBN

Parameter error in { {isbn} }: Invalid ISBN