[[Special:Wantedcategories]] should cover your needs.

[[Special:Wantedcategories]] only shows the first *most* wanted categories, and not the followings.

My proposal should allow to access quickly to all "red" categories in [[Special!:Categories]].

I forgot: the first 1000 *most* wanted categories

from http://en.wikipedia.org/wiki/Special:Wantedcategories , I click one time on (500 next) and, after a second click on this link, I get this message:

<The following information is cached, and was last updated 09:14, 25 February 2008.>

<Discuss this special page at [[Wikipedia talk:Special:Wantedcategories]].>

<See also: Specialpageslist with editable versions.>

<There are no results for this report.>

Maybe there are hundreds of other wanted categories, unreachable from [[Special:Wantedcategories]] (only the the 1000 most wanted).

On EN Wikipedia and [[Special:Categories]], URL seems to be useful: "&offset=Grammar", for example, allows to find "red category" Grammar Schools, cf. http://en.wikipedia.org/w/index.php?title=Special:Categories&offset=Grammar

On other Wikipédias, or those where there are categories with accents or diacritics on some letters, we can also search though "&offset", but who knows that? Example, on FR Wikipedia: http://fr.wikipedia.org/w/index.php?title=Special:Categories&offset=R%E9 (but having only typed "&offet=Ré" in the address bar) Then you can find "red" categories with that URI: Réalité virtuelle, Réchauffement climatique, République Fédérale de Yougoslavie, République romaine.

But other "Special" pages use both "&offset=" in the address bar and a box on the page to reach the same result.

For example: [[Special:Listusers]], where I can 1°) "manually" transform http://en.wikipedia.org/wiki/Special:Listusers (default URL) in http://en.wikipedia.org/w/index.php?title=Special:Listusers&offset=Jimmy or 2°) directly type "Jimmy" in the box after "Display users starting at:".

If it's possible for [[Special:Listusers]], I think it should be also possible for [[Special:Categories]]. Do the Help pages, on any project, show that we can search any category ("red" or existing) by the first letters or digits of its name? I'm not sure, and think that a box should help people.

This is fixed in r35065

This still doesn't work properly. It doesn't process spaces correcly.
For instance, to make the listing start at Cape Verde, one has to manually tweak the url into
http://en.wikipedia.org/w/index.php?title=Special%3ACategories&offset=Cape_Verde
because
http://en.wikipedia.org/w/index.php?title=Special%3ACategories&offset=Cape+Verde
and
http://en.wikipedia.org/w/index.php?title=Special%3ACategories&offset=Cape%20Verde
make the listing start at "Cape".

Besides, perhaps it would be cool to have the listing start in the category referred in the url, not the one immediately next to it.

ayg wrote:

Where did you get the "offset" parameter in the URL? These are the ones generated when you type in the box, and they all work fine.

http://en.wikipedia.org/w/index.php?title=Special%3ACategories&from=Cape_Verde
http://en.wikipedia.org/w/index.php?title=Special%3ACategories&from=Cape+Verde
http://en.wikipedia.org/w/index.php?title=Special%3ACategories&from=Cape%20Verde

At any rate, if there are any bugs in the implementation, or changes you want, please file new bugs (and possibly link to them here). Don't reopen this bug, since the original request is in fact fulfilled.

ayg wrote:

Your first problem was probably fixed in r36111, incidentally. For the other request you can open a new bug.

Looks like my FIXED note didn't make it in here:

Fixed in r36111. Clean up r35065 -- normalize initial caps and _ input on Special:Categories form and accept /suffix on page name.

The earlier quick hack I did just popped the input value into the 'offset' parameter used by the AlphabeticPager system. This was sub-ideal since it didn't normalize input values as nicely, and could get a little funky when paging backwards. Now the input form uses a 'from' parameter (as with Special:Allpages and others) which is nicely normalized.

Also the ability to put the starting point on the subpage suffix (as with Special:Allpages, Special:Prefixindex, etc) is helpful for making in-wiki links, and was added, allowing either input method to work.