Category:Pages with listed invalid ISBNs

This category is populated by ISBNT and ISBN (with parameter ) and by Listed Invalid ISBN,  to indicate that although the given ISBN is malformed it is indeed printed on the work. These malformed ISBNs can still be looked up via Special:BookSources in the usual way despite the prominent warning — it just means that fewer Find this book links will actually work (most libraries will work, most dotcoms won't).

Some ISBNs may still have been printed correctly elsewhere in the same book or corrected in later editions; if further research shows that to be the case (and that the new ISBN still refers to an edition with the same information on the same pages), then the  parameter should be moved or Listed Invalid ISBN should be replaced with ISBN.

This is not an error category and pages in this category should be "fixed" only if the parameter has been misused (see Help:CS1 errors).

Articles are listed in this category when the  parameter is used regardless of the validity of the ISBN.