There are certain circumstances where a redirect, DAB entry or hatnote may be needed.
Redirect, DAB entry or hatnote needed
A redirect, DAB entry or hatnote is generally needed in the following cases:
- Plural to singulars of countable nouns such as Cars>Car, for nouns that are almost never countable a redirect may not be needed but if an article or DAB page exists at the "plural" a DAB entry or hatnote is generally needed.
- Varieties of English, for example British English to American English Petrol>Gasoline.
- "Firstname Lastname" redirects to people who have a different title such as per WP:STAGENAME, Usher Raymond>Usher (musician).
- Full names to their acronyms and initialisms such as National Aeronautics and Space Administration>NASA.
- Long "descriptive" official names to the shorter names such as United Kingdom of Great Britain and Northern Ireland>United Kingdom.
- Former "short" and "long" official names such as Barrow, Alaska>Utqiagvik, Alaska including people who have changed their name.
- Alternative names that are reasonably common such as Kincardine-on-Forth>Kincardine, Fife.
- Topics that include articles in the name such as Gambia>The Gambia and Bug's Life>A Bug's Life.
- Topics that include noun prefixes or suffixes such as Thames>River Thames and Pitcairn>Pitcairn Islands.
- Short names to their full names especially when commonly dropped such as Widecombe>Widecombe in the Moor.
- Topics that are preemptively disambiguated such as Leeds West>Leeds West (UK Parliament constituency) and Bothell>Bothell, Washington.
- Subtitles such as The Gene>The Gene: An Intimate History or On the Social Contract; or, Principles of Political Rights>The Social Contract.
Redirect may be needed
A DAB entry is generally needed in these cases though a redirect may not be. Such redirect may be considered harmless but it may be pointless to create them.
- Topics without definite articles but the topic uses the article as an independent modifier (and readers are very unlikely to expect its part of the name) such as The United Kingdom>United Kingdom, those like The Netherlands>Netherlands where there is a higher likelihood of readers expecting the articles to be part of the name are generally helpful.
- Alternative/incorrect capitalization such as Donald trump>Donald Trump and LONDON>London, in some cases where a trademark owner uses a capitalization (such as all caps) consistently in running text and the others only use the variant in the logo it may be appropriate to make the stylized version redirect to the only company that commonly uses it per MOS:TMSTYLE. Generally its not necessary to create redirect from incorrect capitalization since search goes to the best capitalization match if a perfect one isn't found namely if you typed "Donald trump" or "LONDON" into the search box and the redirect didn't exist it would take you straight to the correct title, see Wikipedia:Naming conventions (capitalization).
- Common misspellings. If a DAB entry is needed generally these are put in the "See also" and if a hatnote is needed generally {{distinguish}} instead of {{about}} or {{for}} is used.
- Redirects from unnecessary disambiguation.
Redirect generally not needed
A DAB entry is generally needed in these cases though a redirect may not be. Such redirect may be kept if they have substantial edit history or were the former location of an article for a reasonable amount of time.
- Redirects from foreign languages such as Blyant>Pencil unless actually used in English such as Serviette>Napkin or the original/official names of things like Deutschland>Germany.
- Titles that include indefinite articles for common nouns such as A frog>Frog, A Number is about the play but there is a hatnote to the DAB A Number (disambiguation) but a hatnote would be needed to Number even if the DAB didn't exist, as can be seen from the play's edit history it was edited to be about the number.
- Uncommon misspellings such as Wiekiepiedia>Wikipedia.
- Titles that are vague/ambiguous/generic.
- Titles that could point to multiple places such as Illness and death>Death, see WP:XY.
Redirects v search
If a term has a particular target that would be more useful than the search results such as a proper noun going to a broader topic (like a WP:1E to the event or a NN song going to an album or the artist) or a plural going to its singular its often better to have a redirect rather than readers getting a list of articles that contain the term/who's content contains the term, if a term is vague/ambiguous/generic its often better not to point these to any article or sometimes even to have a DAB page as the search results are often more helpful however if there is a specific topic that would otherwise be located at the title a DAB page may be needed at the base name to prevent a WP:PRECISION error even though if the specific topic didn't exist a red link may be more helpful, a red link that takes the reader to search results is far less of a WP:SURPRISE than an obscure article at the base name which can also be a mislink magnet as it shows up blue when WP:OVERLINKED instead of showing up red which would be more likely to be noticed thus avoiding an WP:EASTEREGG link.
Redirect better than red link
- Plural to singular as above, see Talk:Novae (fortress)#Requested move 29 June 2020 for another example.
- Proper nouns that only get a mention or redirect per WP:DABMENTION, Talk:Happy Face#Requested move 29 January 2020 an interesting example of a mixture.
- Talk:Misfortune#Requested move 12 March 2016, could redirect to Luck if proper nouns didn't exist?
Red link better than redirect
- Talk:Unlikely#Requested move 16 September 2018
- Talk:Unfulfilled#Requested move 11 December 2018
- Talk:People from Ibiza (song)#Requested move 28 June 2020
- Talk:Murder in Texas (film)#Requested move 30 June 2020, if the film didn't exist this would likely be a redirect like Murder in Vermont but if you search for "Murder in Vermont" (without quotes) you get Felony murder rule (Vermont) first followed by various murders in Vermont and a few related articles but if you type "Murder in Texas" you don't get that. Perhaps a DAB page listing Crime in Texas, Capital punishment in Texas#Capital crimes and Felony murder rule (Texas) (and in this case the film) may be helpful but the term is arguably vague so if the film didn't exist the search results may be enough for readers.
- User talk:Crouch, Swale/Archive 8#Plural settlements some like Denting may be implausible redirects
- Talk:Venting#Requested move 20 August 2015, if the album didn't exist the search function would work and users wouldn't have made links to it