Documentation for Stack Exchange engine URLs?

Question

I have found mentions of various Stack Exchange engine URLs (/question/NNNN, /question/NNNN/question-title-spelled-out, /answer/NNNN, /user/NNNN, /q/NNNN, /a/NNNN, /u/NNNN, etc.) scattered around in different places, including sometimes just-in-passing mentions that a link can also including a user id, /a/NNNN/UUUU or can have suffixes such as ?lastactivity or ?rq=.

Is there some unified location where all these sorts of URLs are documented?

(I did find https://api.stackexchange.com/docs which documents the somewhat-similar-looking API calls, but am trying to find documentation for the regular Stack Exchange engine website URLs instead.)

Answer 1

There is a List of unlinked pages on Stack Exchange sites but it only covers URLs you normally wouldn't find. I don't think there's a unified location document for 'public' URLs, so here's an attempt:

Questions

• Canonical form: /questions/[question ID]/[question title]
  • Most links generated by the site itself have this form (e.g. question lists, sidebar widgets)
  • [question title] is not the full title if it's longer than 80 characters
  • What you type as [question title] doesn't matter; if you type something else, it'll still redirect to the canonical form (which exists for SEO purposes)
  • If you use an answer ID instead of a question ID, it'll still work and redirect to the canonical form (of the answer)
  • Parameters (here is an extended but not up-to-date list, these are the ones I see the most):
    • lq=1: visited from the Linked Questions sidebar widget
    • rq=1: visited from the Related Questions sidebar widget
    • noredirect=1: prevents redirection to original question in the following cases:
      • Questions with no answers closed as duplicates of one question (only active for anonymous users)
      • Questions migrated to other sites (i.e. migration stubs) (always prevented for moderators)
    • lastactivity: links to the last activity (edited post, new answer) on the page
    • cb=1: visited from the Community Bulletin (sidebar widget with Meta posts and blog links)
    • r=SearchResults: visited from a search results page. In this case, a parameter s=[rank]|[relevance] is added as well; see here for more details.
    • answertab=[sort], where [sort] is one of active, oldest, votes, makes sure the right sort is set (regardless of the user's current choice). Often combined with a #tab-top fragment to scroll down to the answers.
• Short form: /q/[question ID] or /q/[question ID]/[user ID]
  • This is the link you get by clicking the share link underneath a question; the user ID is the one currently logged in, not the author. It makes sure the link counts for the Announcer badge and its kin.
  • If you use an answer ID instead of a question ID, it'll still work and redirect to the canonical form (of the answer)
  • If you use the ID of a tag wiki or excerpt, e.g. https://meta.stackexchange.com/questions/62883, it will redirect to the tag info page.
• An obscure form, used in the newsletter: /landing/r/newsletter?cta=question&id=[question ID]

Answers

• Canonical form: /questions/[question ID]/[question title]/[answer ID]#[answer ID]
  • This is basically an extended version of the canonical question URL; again, only the question ID and the last answer ID matter (the latter because it scrolls the page to the right position).
  • The first answer ID matters if there are too many answers to fit on a single page; it makes sure the correct page is displayed.
• Short form: /a/[answer ID] or /a/[answer ID]/[user ID]
  • If you use a question ID instead of an answer ID, it'll still work and redirect to the canonical form (of the question)
  • The global inbox uses this format (with noredirect=1) when somebody posts an answer to one of your questions.

Posts / revisions

• Edit post: /posts/[post ID]/edit
• Revision history: /posts/[post ID]/revisions
  • Can be visited via the 'edited x hours ago' link underneath a post, but works when there is only a single revision too.
  • The global inbox uses this format for notifications that one of your posts has been edited.
• Single revision (rendered): /revisions/[post ID]/[revision number]
• Edit post, starting from a particular revision: /posts/[post ID]/edit/[revision GUID]
• Single revision (markdown): /revisions/[revision GUID]/view-source
• Timeline: /posts/[post ID]/timeline

Comments

• Canonical forms:
  • /questions/[question ID]/[question title]#comment[comment ID]_[question ID]
  • /questions/[question ID]/[question title]/[answer ID]#comment[comment ID]_[answer ID]
  • Most of the remarks about questions and answers applies here, too
• Short form: /posts/comments/[comment ID]
  • This format (with a noredirect=1 parameter) is used in the global inbox.

Users

• Most URLs support current instead of a user ID. This will automatically be populated with the user who is currently logged in, so e.g. /users/current will redirect to your own user page.
• Canonical form: /users/[user ID]/[display name]
  • What you type as [display name] doesn't matter; if you type something else, it'll still redirect to the canonical form (which exists for SEO purposes)
  • For your own user (for ♦ moderators, all users), this shows the Activity page; for other users, the Profile page
  • Navigation is possible with
    • the tab parameter (for the top tab: Profile / Activity and the second Activity tab (Summary / Answers / Questions etc.)
    • the sort parameter (for subtabs; sometimes it does affect the sorting, e.g. answers by votes or by creation date; sometimes it's just an additional filter, e.g. with votes)
    • the page parameter
• Short form: /u/[user ID]
  • Even works for deleted users (♦ moderators are able to view them)
  • Doesn't support current
• Flag summary: /users/flag-summary/[user ID]
  • Normally only works on your own user ID; ♦ moderators can view other users' flag summaries as well.
• Edit profile page: /users/edit/[user ID]
  • Normally only works on your own user ID; ♦ moderators can edit other users' profiles and some of the subpages as well.
  • Edit subpages have their own URL structure, e.g. /users/email/settings/[user ID] for the email settings and /users/delete/[user ID] for the 'Delete account' page.
• Deleted posts: /users/deleted-questions/[user ID] and /users/deleted-answers/[user ID]
  • Normally only works on your own user ID; ♦ moderators can view them for other users as well.