Wikipedia should ideally have, so far as its policies and guidelines allow, an article on every substantial publication that is likely to be used as a source for Wikipedia, and on the author and publisher of every such publication.

The reasons for this are:

(1) It may be difficult or impossible to assess whether any particular source is reliable in any particular respect without having access to as many reviews of it as possible and as much information about its origins as possible. Collecting such information is time consuming.

(2) If Wikipedia does not have such articles in relation to a source, then the references to that source included in other articles are almost meaningless to the reader, because they do not demonstrate, for their benefit, that the source actually is reliable.

Paragraph (1) applies to unreliable sources which are likely to be mistaken for reliable ones. In those cases, an article has the effect of putting a "health warning" on them.

The foregoing does not apply in cases where it is not possible to say something meaningful about the publication, author or publisher.