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Shortcuts: WP:CNR WP:CNS WP:CROSS

Cross-namespace redirects are redirects that redirect from one namespace to another (although the term is most often applied to redirects that go from the main (article) namespace to the project namespace). There have been various debates over the use of cross-namespace redirects,¹ and the issue remains moderately controversial.

Currently, the general consensus seems to be that newly created cross-namespace redirects should be deleted (although very old ones might retain value for extra-Wikipedia links), and that Pseudo-namespace redirects (CAT:, P:, MOS:, etc) may freely be used.

See also a historical proposal for a solution to this problem.

Overview of the debate

Arguments for deleting CNRs

Related guidelines: Wikipedia:Avoid self-references, Wikipedia:Redirects#When should we delete a redirect? delete#5, Wikipedia:Verbatim copying

• CNRs are bad because they result in a person (reader) walking around a building (encyclopedia) and falling into the pipework (project space) because the builders (editors) thought cracks in the walls and floors would be useful for them to get around.
• Namespaces were created for a reason, so that the encyclopedic content would be separate.² CNRs work against this.
• The filters exist for a reason, to fine-tune search results. And some encyclopedic searches return a majority of Wikipedia pages because of all of the cross-namespace redirects; the user shouldn't have to filter through manually, that's what the filters are for.³ Search filters should work, not return extraneous results.⁴ (For example, searching the encyclopedia for a term "page update" (which is hardly a wikipedia specific term) will return CNR's as the first four results, and we should not be requiring readers to sift through non-encyclopedic background noise when they were explicitly searching the encyclopedia.⁵) For the reader who has deliberately unselected the box because they don't want Wikipedia results, it is unfair to return them anyway. With CNRs, a reader can choose to search Wikipedia by ticking the box, but they have no option not to do so. Without CNRs, readers wishing to search Wikipedia can do so, and those who do not want to can also do so. Thus, the existence of CNRs removes choice.⁶
• Some mirrors duplicate the main article namespace but not the project namespace. Thus, cross-namespace redirects end up creating thousands of broken links on mirrors. Per WP:SRTA we should link to stuff outside of the article namespace with external links; see Wikipedia as an example.

Arguments for keeping CNRs

Related guideline: Wikipedia:Redirects#When should we delete a redirect? keep#5

• Many CNRs are very unlikely search terms when looking for articles anyway. If someone searches for "articles for deletion", it's only logical that he is looking for Wikipedia:Articles for deletion, and not for any encyclopaedia article. This is essentially a counter-argument to the first argument for deleting CNRs.
• Useful to some people. One purpose of WP is to explain obscure references.⁷
• Otherwise the newbie users for whom these redirects are useful would be left up the creek.⁸ In most cases, users who type such names in the search box expect to be taken to its other-namespace target.⁹
• CNRs aid in accidental linking.¹⁰
• They're easier to type.
• If they're acceptable, then Wikipedia requires no policy on cross-namespace redirects. Simplifying policy improves odds that newbies and policy non-wonks understand/follow policy.
• Often, the redirect is a holdover from before the creation of the alternate namespace version. The redirect may hold history of the page. (WP:R keep #1)

Doesn't that make it a candidate for history merging? - Mgm|^(talk) 10:35, 22 August 2006 (UTC)

• For redirects which have been extensively used on Talk and User pages, the cost of orphaning the redirect is high.
• Redirects which are used exclusively on User, Talk and other project pages do not create confusion. Readers of the article-space only (whether at Wikipedia or through a mirror which only copies our article-space) will never fall into this "pipework" because these "cracks" (or more accurately, "access ports") are only being left in the maintenance corridors.

Technical details

• Currently the default search filter is set to main namespace only.
• Wikipedia has many more readers than editors.¹¹

Notes

1. ^ See debates regarding pages entitled "Redirect archives", "Votes for deletion" and several others.
2. ^ based on this diff
3. ^ based on this diff
4. ^ based on this diff
5. ^ based on this diff
6. ^ based on this diff
7. ^ based on this diff
8. ^ based on this diff
9. ^ based on this diff
10. ^ based on this diff
11. ^ See traffic rankings.