Category:Articles with invalid ISMNs

This is a maintenance category, used for maintenance of the Wikipedia project. It is not part of the encyclopedia and contains non-article pages, or groups articles by status rather than subject. Do not include this category in content categories. This is a tracking category. It builds and maintains a list of pages primarily for the sake of the list itself. They are not part of the encyclopedia's categorization scheme. This category is hidden on its member pages—unless the corresponding user preference (Appearance → Show hidden categories) is set. These categories can be used to track, build and organize lists of pages needing "attention en masse" (for example, pages using deprecated syntax), or that may need to be edited at someone's earliest convenience. These categories also serve to aggregate members of several lists or sub-categories into a larger, more efficient list (discriminated by classifications).

Administrators: Please do not delete this category as empty! This category may be empty occasionally or even most of the time.

This is a maintenance category of articles with invalid ISMNs. It is often included by means of the template {{Please check ISMN}}, which should be located next to the ISMN with the problem.

Articles can also be included in this category if an ISMN within the {{ISMN}} template is not valid.

The most likely reason is a bad checksum, (see ISMN) which probably means there is a typing error in the ISMN.

See also Category:CS1 errors: ISMN