Merge branch 'docs/guidance-for-unavailable-links' into 'master'

Avoid links requiring permissions

Closes #59653

See merge request gitlab-org/gitlab-ce!27797

doc/development/documentation/styleguide.md

@@ -362,16 +362,23 @@ For other punctuation rules, please refer to the
   E.g., instead of writing something like `Read more about GitLab Issue Boards [here](LINK)`,
   write `Read more about [GitLab Issue Boards](LINK)`.
 
-### Links to confidential issues
+### Links requiring permissions
 
-Don't link directly to [confidential issues](../../user/project/issues/confidential_issues.md). These will fail for:
+Don't link directly to:
+
+- [Confidential issues](../../user/project/issues/confidential_issues.md).
+- Project features that require [special permissions](../../user/permissions.md) to view.
+
+These will fail for:
 
 - Those without sufficient permissions.
 - Automated link checkers.
 
 Instead:
 
-- Mention in the text that the information is contained in a confidential issue. This will reduce confusion.
+- To reduce confusion, mention in the text that the information is either:
+  - Contained in a confidential issue.
+  - Requires special permission to a project to view.
 - Provide a link in back ticks (`` ` ``) so that those with access to the issue can easily navigate to it.
 
 Example:

doc/development/testing_guide/end_to_end_tests.md

@@ -99,13 +99,13 @@ subgraph gitlab-qa pipeline
 
 1. When packages are ready, and available in the registry, a final step in the
    [Omnibus GitLab][omnibus-gitlab] pipeline, triggers a new
-   [GitLab QA pipeline][gitlab-qa-pipelines]. It also waits for a resulting status.
+   GitLab QA pipeline (those with access can view them at `https://gitlab.com/gitlab-org/gitlab-qa/pipelines`). It also waits for a resulting status.
 
 1. GitLab QA pulls images from the registry, spins-up containers and runs tests
    against a test environment that has been just orchestrated by the `gitlab-qa`
    tool.
 
-1. The result of the [GitLab QA pipeline][gitlab-qa-pipelines] is being
+1. The result of the GitLab QA pipeline is being
    propagated upstream, through Omnibus, back to the CE / EE merge request.
 
 #### Using the `review-qa-all` jobs
@@ -146,7 +146,6 @@ you can find an issue you would like to work on in
 
 [omnibus-gitlab]: https://gitlab.com/gitlab-org/omnibus-gitlab
 [gitlab-qa]: https://gitlab.com/gitlab-org/gitlab-qa
-[gitlab-qa-pipelines]: https://gitlab.com/gitlab-org/gitlab-qa/pipelines
 [gitlab-qa-readme]: https://gitlab.com/gitlab-org/gitlab-qa/tree/master/README.md
 [quality-nightly-pipelines]: https://gitlab.com/gitlab-org/quality/nightly/pipelines
 [quality-staging-pipelines]: https://gitlab.com/gitlab-org/quality/staging/pipelines