[8.5] [DOCS] Assign users to Security cases (backport #2568)

docs/cases/cases-manage.asciidoc

@@ -11,16 +11,19 @@ Open a new case to keep track of security issues and share their details with
 colleagues.
 
 . Go to *Cases*, then click *Create case*. If no cases exist, the Cases table will be empty and you'll be prompted to create one by clicking the *Create case* button inside the table.
-. Give the case a name, add relevant tags, assign a severity level, and provide a description. You can use
+. Give the case a name, assign a severity level, and provide a description. You can use
 https://www.markdownguide.org/cheat-sheet[Markdown] syntax in the case description.
 +
 NOTE: If you do not assign your case a severity level, it will be assigned *Low* by default.
 
 +
 TIP: You can insert a Timeline link in the case description by clicking the Timeline icon (image:images/add-timeline-button.png[Timeline icon,17,17]).
 
+. Optionally, add assignees and relevant tags. You can add users only if they
+meet the necessary <<case-permissions,prerequisites>>.
+
 . Choose if you want alert statuses to sync with the case's status after they are added to the case. This option is enabled by default, but you can turn it off after creating the case.
-. From *External incident management*, select a <<cases-ui-integrations, connector>>. If you’ve previously added one, that connector displays as the default selection. Otherwise, the default setting is `No connector selected`.
+. From *External incident management*, select a <<cases-ui-integrations,connector>>. If you've previously added one, that connector displays as the default selection. Otherwise, the default setting is `No connector selected`.
 . Click *Create case*.
 +
 NOTE: If you've selected a connector for the case, the case is automatically pushed to the third-party system it's connected to.
@@ -33,7 +36,9 @@ image::images/cases-ui-open.png[Shows an open case]
 [[cases-ui-manage]]
 == Manage existing cases
 
-From the Cases page, you can search existing cases and filter them by severity, tags, reporter, and status: `Open`, `In progress`, or `Closed`. General case metrics, including how long it takes to close cases, are provided above the table.
+From the Cases page, you can search existing cases and filter them by assignee,
+severity, status, and tags. General case metrics, including how long it takes to
+close cases, are provided above the table.
 
 [role="screenshot"]
 image::images/cases-home-page.png[Case UI Home]
@@ -45,10 +50,11 @@ To explore a case, click on its name. You can then:
 +
 TIP: Comments can contain Markdown. For syntax help, click the Markdown icon (image:images/markdown-icon.png[Click markdown icon,17,17]) in the bottom right of the comment.
 
-* <<cases-examine-alerts, Examine alerts attached to the case>>
+* <<cases-examine-alerts,Examine alerts attached to the case>>
 * <<cases-lens-visualization>>
 * Modify the case's description
-* <<cases-ui-integrations, Manage connectors>> and send updates to external systems (if you've added a connector to the case)
+* Add or remove assignees
+* <<cases-ui-integrations,Manage connectors>> and send updates to external systems (if you've added a connector to the case)
 * Close the case or reopen it
 * Edit tags
 * Update the case's severity

docs/cases/cases-overview.asciidoc

@@ -3,7 +3,7 @@
 
 = Cases
 
-Collect and share information about security issues by opening a case in {elastic-sec}. Cases allow you to track key investigation details, collect alerts in a central location, and more. The {elastic-sec} UI provides several ways to create and manage cases. Alternatively, you can use the <<cases-api-overview, Cases API>> to perform the same tasks.
+Collect and share information about security issues by opening a case in {elastic-sec}. Cases allow you to track key investigation details, collect alerts in a central location, and more. The {elastic-sec} UI provides several ways to create and manage cases. Alternatively, you can use the <<cases-api-overview,cases API>> to perform the same tasks.
 
 You can also send cases to these external systems by <<cases-ui-integrations, configuring external connectors>>:
 

docs/getting-started/cases-req.asciidoc

@@ -22,16 +22,23 @@ To grant access to cases, set the {kib} space privileges for the *Cases* and *{c
 | Action      | {kib} Privileges
 | Give full access to manage cases
 a|
-* `All` for the *Cases* feature
-* `All` for the *{connectors-feature}* feature (go to *Management > {connectors-feature}* to set this)
+* `All` for the *Cases* feature under *Security*
+* `All` for the *{connectors-feature}* feature under *Management*
 
 NOTE: Roles without `All` *{connectors-feature}* feature privileges cannot create, add, delete, or modify case connectors.
 
-| Give view-only access for cases | `Read` for the *Cases* feature
+| Give assignee access to cases
+a|
+* `All` for the *Cases* feature under *Security*
+
+NOTE: Before a user can be assigned to a case, they must log into {kib} at least
+once, which creates a user profile.
+
+| Give view-only access for cases | `Read` for the *Cases* feature under *Security*
 
-| Give access to view and delete cases | `Read` for the *Cases* feature and the *Delete* sub-feature selected
+| Give access to view and delete cases | `Read` for the *Cases* feature under *Security* with the *Delete* sub-feature selected
 
-| Revoke all access to cases | `None` for the *Cases* feature |
+| Revoke all access to cases | `None` for the *Cases* feature under *Security*
 
 |==============================================