Adding in caveats for removing users

We don't note in our documentation about how removing a user does
not remove an existing fork relationship.

doc/user/group/index.md

@@ -650,17 +650,20 @@ By default, projects in a group can be forked.
 Optionally, on [Premium](https://about.gitlab.com/pricing/) or higher tiers,
 you can prevent the projects in a group from being forked outside of the current top-level group.
 
-Previously this setting was available only for groups enforcing group managed account. This setting will be
-removed from SAML setting page and migrated to group settings. In the interim period, both of these settings are taken into consideration.
-If even one is set to `true` then it will be assumed the group does not allow forking projects outside.
+Previously, this setting was available only for groups enforcing group managed
+account. This setting will be removed from the SAML setting page, and migrated to the
+group settings page. In the interim period, both of these settings are taken into consideration.
+If even one is set to `true`, then the group does not allow outside forks.
 
-To enable prevent project forking:
+To prevent projects from being forked outside the group:
 
 1. Go to the top-level group's **Settings > General** page.
 1. Expand the **Permissions, LFS, 2FA** section.
 1. Check **Prevent project forking outside current group**.
 1. Select **Save changes**.
 
+Existing forks are not removed.
+
 ## Group push rules **(PREMIUM)**
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/34370) in GitLab 12.8.

doc/user/project/members/index.md

@@ -107,7 +107,7 @@ If a user is a direct member of a project, you can remove them.
 If membership is inherited from a parent group, then the member can be removed only from the parent
 group itself.
 
-Prerequisite:
+Prerequisites:
 
 - You must have the [Owner role](../../permissions.md).
 - Optional. Unassign the member from all issues and merge requests that
@@ -117,7 +117,13 @@ To remove a member from a project:
 
 1. Go to your project and select **Project information > Members**.
 1. Next to the project member you want to remove, select **Remove member** **{remove}**.
-1. Optional. In the confirmation box, select the **Also unassign this user from related issues and merge requests** checkbox.
+1. Optional. In the confirmation box, select the
+   **Also unassign this user from related issues and merge requests** checkbox.
+1. To prevent leaks of sensitive information from private projects, verify the
+   user has not forked the private repository. Existing forks continue to receive
+   changes from the upstream project. You may also want to configure your project
+   to prevent projects in a group
+   [from being forked outside their group](../../group/index.md#prevent-project-forking-outside-group).
 1. Select **Remove member**.
 
 ## Filter and sort members