diff --git a/config/locales/en.yml b/config/locales/en.yml
index bfca26aeffaf..a397818825ec 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -2025,6 +2025,7 @@ en:
   label_member_new: "New member"
   label_member_all_admin: "(All roles due to admin status)"
   label_member_plural: "Members"
+  label_membership_plural: "Memberships"
   lable_membership_added: "Member added"
   lable_membership_updated: "Member updated"
   label_menu_badge:
diff --git a/docs/api/apiv3/components/examples/group-response.yml b/docs/api/apiv3/components/examples/group-response.yml
new file mode 100644
index 000000000000..46277c8082f6
--- /dev/null
+++ b/docs/api/apiv3/components/examples/group-response.yml
@@ -0,0 +1,42 @@
+# Example: GroupResponse
+---
+value:
+  _type: Group
+  id: 26
+  name: Force Users
+  createdAt: '2024-01-11T15:54:16.542Z'
+  updatedAt: '2024-01-11T15:58:02.237Z'
+  _embedded:
+    members:
+      - _hint: Principal resource shortened for brevity
+        _type: User
+        id: 23
+        name: Grogu Jarin
+      - _hint: Principal resource shortened for brevity
+        _type: User
+        id: 14
+        name: Mara Jade
+      - _hint: Principal resource shortened for brevity
+        _type: User
+        id: 3
+        name: Darth Vader
+  _links:
+    self:
+      href: '/api/v3/groups/26'
+      title: Force Users
+    memberships:
+      href: '/api/v3/memberships?filters=%5B%7B%22principal%22%3A%7B%22operator%22%3A%22%3D%22%2C%22values%22%3A%5B%2226%22%5D%7D%7D%5D'
+      title: Memberships
+    delete:
+      href: '/api/v3/groups/26'
+      method: delete
+    updateImmediately:
+      href: '/api/v3/groups/26'
+      method: patch
+    members:
+      - href: '/api/v3/users/23'
+        title: Grogu Jarin
+      - href: '/api/v3/users/14'
+        title: Mara Jade
+      - href: '/api/v3/users/3'
+        title: Darth Vader
diff --git a/docs/api/apiv3/components/examples/placeholder-user-response.yml b/docs/api/apiv3/components/examples/placeholder-user-response.yml
new file mode 100644
index 000000000000..33052d030f2e
--- /dev/null
+++ b/docs/api/apiv3/components/examples/placeholder-user-response.yml
@@ -0,0 +1,26 @@
+# Example: PlaceholderUserResponse
+---
+value:
+  _type: PlaceholderUser
+  id: 27
+  name: Akolyth
+  createdAt: '2024-02-12T11:52:24.708Z'
+  updatedAt: '2024-02-12T11:52:24.708Z'
+  _links:
+    self:
+      href: '/api/v3/placeholder_users/27'
+      title: Akolyth
+    memberships:
+      href: '/api/v3/memberships?filters=%5B%7B%22principal%22%3A%7B%22operator%22%3A%22%3D%22%2C%22values%22%3A%5B%2227%22%5D%7D%7D%5D'
+      title: Memberships
+    updateImmediately:
+      href: '/api/v3/placeholder_users/27'
+      title: Update Akolyth
+      method: patch
+    delete:
+      href: '/api/v3/placeholder_users/27'
+      title: Delete Akolyth
+      method: delete
+    showUser:
+      href: '/placeholder_users/27'
+      type: text/html
diff --git a/docs/api/apiv3/components/examples/user-response.yml b/docs/api/apiv3/components/examples/user-response.yml
new file mode 100644
index 000000000000..729d29afba41
--- /dev/null
+++ b/docs/api/apiv3/components/examples/user-response.yml
@@ -0,0 +1,39 @@
+# Example: UserResponse
+---
+value:
+  _type: User
+  id: 14
+  name: Mara Jade
+  createdAt: '2022-04-04T08:07:22.910Z'
+  updatedAt: '2024-02-09T09:01:17.382Z'
+  login: member
+  admin: false
+  firstName: Mara
+  lastName: Jade
+  email: m.jade@empire.org
+  avatar: 'https://secure.gravatar.com/avatar/17dd23570f3bd129d06db9b48b7a41b8?default=404&secure=true'
+  status: active
+  identityUrl: null
+  language: en
+  _links:
+    self:
+      href: '/api/v3/users/14'
+      title: Mara Jade
+    memberships:
+      href: '/api/v3/memberships?filters=%5B%7B%22principal%22%3A%7B%22operator%22%3A%22%3D%22%2C%22values%22%3A%5B%2214%22%5D%7D%7D%5D'
+      title: Memberships
+    showUser:
+      href: '/users/14'
+      type: text/html
+    updateImmediately:
+      href: '/api/v3/users/14'
+      title: Update member
+      method: patch
+    lock:
+      href: '/api/v3/users/14/lock'
+      title: Set lock on member
+      method: post
+    delete:
+      href: '/api/v3/users/14'
+      title: Delete member
+      method: delete
diff --git a/docs/api/apiv3/components/schemas/group_collection_model.yml b/docs/api/apiv3/components/schemas/group_collection_model.yml
index 358bed756054..7a9b17d4a139 100644
--- a/docs/api/apiv3/components/schemas/group_collection_model.yml
+++ b/docs/api/apiv3/components/schemas/group_collection_model.yml
@@ -14,11 +14,11 @@ allOf:
         properties:
           self:
             allOf:
-              - $ref: "./link.yml"
+              - $ref:  './link.yml'
               - description: |-
                   This group collection
 
-                  **Resource**: GroupCollectionReadModel
+                  **Resource**: Collection
       _embedded:
         type: object
         required:
diff --git a/docs/api/apiv3/components/schemas/group_model.yml b/docs/api/apiv3/components/schemas/group_model.yml
index bb2753286c99..e5818c4f088b 100644
--- a/docs/api/apiv3/components/schemas/group_model.yml
+++ b/docs/api/apiv3/components/schemas/group_model.yml
@@ -1,107 +1,57 @@
 # Schema: GroupModel
 ---
-type: object
-required:
-  - _type
-  - id
-  - _links
-properties:
-  id:
-    type: integer
-    description: The group id
-    minimum: 1
-  name:
-    type: string
-    description: |-
-      Group's full name, formatting depends on instance settings
-
-      # Conditions
-      - admin
-  createdAt:
-    type: string
-    format: date-time
-    description: |-
-      Time of creation
-
-      # Conditions
-      - admin
-  updatedAt:
-    type: string
-    format: date-time
-    description: Time of the most recent change to the user
-  _links:
-    type: object
+allOf:
+  - $ref: './principal_model.yml'
+  - type: object
     required:
-      - self
+      - _type
+      - _embedded
     properties:
-      self:
-        allOf:
-          - $ref: './link.yml'
-          - description: |-
-              This group resource
-
-              **Resource**: Group
-      delete:
-        allOf:
-          - $ref: './link.yml'
-          - description: |-
-              Deletes the group.
-
-              # Conditions
-              **Permission**: Administrator
-      updateImmediately:
-        allOf:
-          - $ref: './link.yml'
-          - description: |-
-              Updates the group's attributes.
-
-              # Conditions
-              **Permission**: Administrator
-      memberships:
-        allOf:
-          - $ref: './link.yml'
-          - description: |-
-              Link to collection of all the group's memberships. The list will only include the memberships in projects
-              in which the requesting user has the necessary permissions.
-
-              **Resource**: MemberCollection
-
-              # Conditions
-              **Permission**: `view members` or `manage members` in any project
-      members:
-        type: array
-        items:
-          allOf:
-            - $ref: './link.yml'
-            - description: |-
-                One of the members of the group.
-
-                **Resource**: User
-
-                # Conditions
-                **Permission**: `manage members` in any project to read & admin to write
-
-example:
-  _type: Group
-  id: 9
-  name: Stormtroopers
-  createdAt: '2022-09-23T11:06:36.024Z'
-  updatedAt: '2022-09-23T11:06:36.024Z'
-  _links:
-    self:
-      href: '/api/v3/groups/9'
-      title: Stormtroopers
-    delete:
-      href: '/api/v3/group/9'
-      method: delete
-    memberships:
-      href: '/api/v3/memberships?filters=[{"principal":{"operator":"=","values":["9"]}}]'
-      title: Memberships
-    updateImmediately:
-      href: '/api/v3/group/9'
-      method: patch
-    members:
-      - href: '/api/v3/users/363'
-        title: ST-097E
-      - href: '/api/v3/users/60'
-        title: ST-C-334
+      _type:
+        type: string
+        enum:
+          - Group
+      _embedded:
+        type: object
+        properties:
+          members:
+            type: array
+            description: Embedded list of members.
+            items:
+              - $ref: './user_model.yml'
+      _links:
+        type: object
+        properties:
+          members:
+            type: array
+            items:
+              allOf:
+                - $ref: './link.yml'
+                - description: |-
+                    A member of the group
+
+                    # Conditions:
+
+                    - user has permission `manage_members` in any project
+
+                    **Resource**: User
+          delete:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  An href to delete the group.
+
+                  # Conditions:
+
+                  - `admin`
+          updateImmediately:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  An href to update the group.
+
+                  # Conditions:
+
+                  - `admin`
+
+                  **Resource**: Group
diff --git a/docs/api/apiv3/components/schemas/placeholder_user_collection_model.yml b/docs/api/apiv3/components/schemas/placeholder_user_collection_model.yml
new file mode 100644
index 000000000000..36a2bf177682
--- /dev/null
+++ b/docs/api/apiv3/components/schemas/placeholder_user_collection_model.yml
@@ -0,0 +1,46 @@
+# Schema: PlaceholderUserCollectionModel
+---
+allOf:
+  - $ref: './collection_model.yml'
+  - type: object
+    required:
+      - _links
+      - _embedded
+    properties:
+      _links:
+        type: object
+        required:
+          - self
+        properties:
+          self:
+            allOf:
+              - $ref: "./link.yml"
+              - description: |-
+                  This placeholder user collection
+                  
+                  **Resource**: Collection
+      _embedded:
+        type: object
+        required:
+          - elements
+        properties:
+          elements:
+            type: array
+            items:
+              $ref: './placeholder_user_model.yml'
+
+example:
+  _type: Collection
+  total: 2
+  count: 2
+  _links:
+    self:
+      href: '/api/v3/placeholder_users'
+  _embedded:
+    elements:
+      - _hint: PlaceholderUser resource shortened for brevity
+        _type: PlaceholderUser
+        id: 1337
+      - _hint: PlaceholderUser resource shortened for brevity
+        _type: PlaceholderUser
+        id: 1338
diff --git a/docs/api/apiv3/components/schemas/placeholder_user_create_model.yml b/docs/api/apiv3/components/schemas/placeholder_user_create_model.yml
new file mode 100644
index 000000000000..be2fd48855ac
--- /dev/null
+++ b/docs/api/apiv3/components/schemas/placeholder_user_create_model.yml
@@ -0,0 +1,7 @@
+# Schema: PlaceholderUserCreateModel
+---
+type: object
+properties:
+  name:
+    type: string
+    description: The new name of the placeholder user to be created.
diff --git a/docs/api/apiv3/components/schemas/placeholder_user_model.yml b/docs/api/apiv3/components/schemas/placeholder_user_model.yml
new file mode 100644
index 000000000000..7193afd18cc2
--- /dev/null
+++ b/docs/api/apiv3/components/schemas/placeholder_user_model.yml
@@ -0,0 +1,50 @@
+# Schema: PlaceholderUserModel
+---
+allOf:
+  - $ref: './principal_model.yml'
+  - type: object
+    required:
+      - _type
+    properties:
+      _type:
+        type: string
+        enum:
+          - PlaceholderUser
+      status:
+        type: string
+        description: |-
+          The current activation status of the placeholder user.
+
+          # Conditions
+
+          - User has `manage_placeholder_user` permission globally
+      _links:
+        type: object
+        required:
+          - showUser
+        properties:
+          showUser:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  A relative path to show the placeholder user in the web application.
+          delete:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  An href to delete the placeholder user.
+
+                  # Conditions:
+
+                  - `manage_placeholder_user`
+          updateImmediately:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  An href to update the placeholder user.
+
+                  # Conditions:
+
+                  - `manage_placeholder_user`
+
+                  **Resource**: PlaceholderUser
diff --git a/docs/api/apiv3/components/schemas/principal_collection_model.yml b/docs/api/apiv3/components/schemas/principal_collection_model.yml
new file mode 100644
index 000000000000..7ca06dde3128
--- /dev/null
+++ b/docs/api/apiv3/components/schemas/principal_collection_model.yml
@@ -0,0 +1,53 @@
+# Schema: PrincipalCollectionModel
+---
+allOf:
+  - $ref: './collection_model.yml'
+  - type: object
+    required:
+      - _links
+      - _embedded
+    properties:
+      _links:
+        type: object
+        required:
+          - self
+          - representations
+        properties:
+          self:
+            allOf:
+              - $ref: "./link.yml"
+              - description: |-
+                  This principal collection
+                  
+                  **Resource**: Collection
+      _embedded:
+        type: object
+        required:
+          - elements
+        properties:
+          elements:
+            type: array
+            items:
+              anyOf:
+                - $ref: './user_model.yml'
+                - $ref: './placeholder_user_model.yml'
+                - $ref: './group_model.yml'
+
+example:
+  _type: Collection
+  total: 3
+  count: 3
+  _links:
+    self:
+      href: '/api/v3/principals'
+  _embedded:
+    elements:
+      - _hint: User resource shortened for brevity
+        _type: User
+        id: 1337
+      - _hint: Group resource shortened for brevity
+        _type: Group
+        id: 1338
+      - _hint: PlaceholderUser resource shortened for brevity
+        _type: PlaceholderUser
+        id: 1339
diff --git a/docs/api/apiv3/components/schemas/principal_model.yml b/docs/api/apiv3/components/schemas/principal_model.yml
new file mode 100644
index 000000000000..10f31f6e821f
--- /dev/null
+++ b/docs/api/apiv3/components/schemas/principal_model.yml
@@ -0,0 +1,53 @@
+# Schema: PrincipalModel
+---
+type: object
+required:
+  - _type
+  - id
+  - name
+  - _links
+properties:
+  _type:
+    type: string
+    enum:
+      - User
+      - Group
+      - PlaceholderUser
+  id:
+    type: integer
+    description: The principal's unique identifier.
+    minimum: 1
+  name:
+    type: string
+    description: The principal's display name, layout depends on instance settings.
+  createdAt:
+    type: string
+    format: date-time
+    description: Time of creation
+  updatedAt:
+    type: string
+    format: date-time
+    description: Time of the most recent change to the principal
+  _links:
+    type: object
+    required:
+      - self
+    properties:
+      self:
+        allOf:
+          - $ref: './link.yml'
+          - description: |-
+              This principal resource.
+
+              **Resource**: User|Group|PlaceholderUser
+      memberships:
+        allOf:
+          - $ref: './link.yml'
+          - description: |-
+              An href to the collection of the principal's memberships.
+              
+              # Conditions:
+              
+              - user has permission `view_members` or `manage_members` in any project
+              
+              **Resource**: Collection
diff --git a/docs/api/apiv3/components/schemas/principals_model.yml b/docs/api/apiv3/components/schemas/principals_model.yml
deleted file mode 100644
index f18694db82fe..000000000000
--- a/docs/api/apiv3/components/schemas/principals_model.yml
+++ /dev/null
@@ -1,94 +0,0 @@
-# Schema: PrincipalsModel
----
-type: object
-example:
-  _type: Collection
-  total: 4
-  count: 4
-  _embedded:
-    elements:
-    - _type: User
-      id: 4
-      login: Eliza92778
-      admin: false
-      firstName: Danika
-      lastName: O'Keefe
-      name: Danika O'Keefe
-      email: jackie@dicki.org
-      avatar: https://example.org/users/4/avatar
-      createdAt: '2015-03-20T12:57:02.646Z'
-      updatedAt: '2015-06-16T15:28:14.550Z'
-      status: active
-      identityUrl:
-      _links:
-        self:
-          href: "/api/v3/users/4"
-          title: Danika O'Keefe
-        showUser:
-          href: "/users/4"
-          type: text/html
-        updateImmediately:
-          href: "/api/v3/users/4"
-          title: Update Eliza92778
-          method: patch
-        lock:
-          href: "/api/v3/users/4/lock"
-          title: Set lock on Eliza92778
-          method: post
-        delete:
-          href: "/api/v3/users/4"
-          title: Delete Eliza92778
-          method: delete
-    - _type: User
-      id: 2
-      login: Sebastian9686
-      admin: false
-      firstName: Peggie
-      lastName: Feeney
-      name: Peggie Feeney
-      email:
-      avatar: https://example.org/users/4/avatar
-      createdAt: '2015-03-20T12:56:55.963Z'
-      updatedAt: '2015-03-20T12:56:55.963Z'
-      status: active
-      identityUrl:
-      _links:
-        self:
-          href: "/api/v3/users/2"
-          title: Peggie Feeney
-        showUser:
-          href: "/users/2"
-          type: text/html
-        updateImmediately:
-          href: "/api/v3/users/2"
-          title: Update Sebastian9686
-          method: patch
-        lock:
-          href: "/api/v3/users/2/lock"
-          title: Set lock on Sebastian9686
-          method: post
-        delete:
-          href: "/api/v3/users/2"
-          title: Delete Sebastian9686
-          method: delete
-    - _type: Group
-      id: 9
-      name: The group
-      createdAt: '2015-09-23T11:06:36.687Z'
-      updatedAt: '2015-09-23T11:06:36.687Z'
-      _links:
-        self:
-          href: "/api/v3/groups/9"
-          title: The group
-    - _type: PlaceholderUser
-      id: 29
-      name: UX Designer
-      createdAt: '2018-09-23T11:06:36.687Z'
-      updatedAt: '2019-10-23T11:06:36.687Z'
-      _links:
-        self:
-          href: "/api/v3/placeholder_users/29"
-          title: UX Designer
-  _links:
-    self:
-      href: "/api/v3/principals"
diff --git a/docs/api/apiv3/components/schemas/project_collection_model.yml b/docs/api/apiv3/components/schemas/project_collection_model.yml
index 298bfa547189..ec34cb9e5b4f 100644
--- a/docs/api/apiv3/components/schemas/project_collection_model.yml
+++ b/docs/api/apiv3/components/schemas/project_collection_model.yml
@@ -15,16 +15,16 @@ allOf:
         properties:
           self:
             allOf:
-              - $ref: "./link.yml"
+              - $ref: './link.yml'
               - description: |-
-                  This file links collection
+                  This project collection
                   
                   **Resource**: ProjectStorageCollectionModel
           representations:
             type: array
             items:
               allOf:
-                - $ref: "./link.yml"
+                - $ref: './link.yml'
                 - description: |-
                     A project collection representation in a specific file format.
       _embedded:
diff --git a/docs/api/apiv3/components/schemas/user_collection_model.yml b/docs/api/apiv3/components/schemas/user_collection_model.yml
index e6aa2ab589d4..f803db5f7ac9 100644
--- a/docs/api/apiv3/components/schemas/user_collection_model.yml
+++ b/docs/api/apiv3/components/schemas/user_collection_model.yml
@@ -14,11 +14,11 @@ allOf:
         properties:
           self:
             allOf:
-              - $ref: "./link.yml"
+              - $ref: './link.yml'
               - description: |-
                   This user collection
                   
-                  **Resource**: UserCollectionModel
+                  **Resource**: Collection
       _embedded:
         type: object
         required:
diff --git a/docs/api/apiv3/components/schemas/user_model.yml b/docs/api/apiv3/components/schemas/user_model.yml
index f93995ce4ac7..97a850cb8a4e 100644
--- a/docs/api/apiv3/components/schemas/user_model.yml
+++ b/docs/api/apiv3/components/schemas/user_model.yml
@@ -1,201 +1,163 @@
 # Schema: UserModel
 ---
-type: object
-required:
-  - _type
-  - id
-  - name
-  - avatar
-  - _links
-properties:
-  _type:
-    type: string
-    enum:
-      - User
-  id:
-    type: integer
-    description: User's id
-    minimum: 0
-  login:
-    type: string
-    description: |-
-      User's login name
-
-      # Conditions
-
-      **Permission**: Administrator, manage_user global permission
-    maxLength: 256
-  firstName:
-    type: string
-    description: |-
-      User's first name
-
-      # Conditions
-
-      **Permission**: Administrator, manage_user global permission
-    maxLength: 30
-  lastName:
-    type: string
-    description: |-
-      User's last name
-
-      # Conditions
-
-      **Permission**: Administrator, manage_user global permission
-    maxLength: 30
-  name:
-    type: string
-    description: User's full name, formatting depends on instance settings
-  email:
-    type: string
-    description: |-
-      User's email address
-
-      # Conditions
-
-      E-Mail address not hidden, **Permission**: Administrator, manage_user global permission
-    maxLength: 60
-  admin:
-    type: boolean
-    description: |-
-      Flag indicating whether or not the user is an admin
-
-      # Conditions
-
-      **Permission**: Administrator
-  avatar:
-    type: string
-    format: uri
-    description: URL to user's avatar
-  status:
-    type: string
-    description: The current activation status of the user (see below)
-  language:
-    type: string
-    description: |-
-      User's language | ISO 639-1 format
-
-      # Conditions
-
-      **Permission**: Administrator, manage_user global permission
-  identityUrl:
-    type:
-      - 'string'
-      - 'null'
-    description: |-
-      User's identity_url for OmniAuth authentication
-
-      # Conditions
-
-      **Permission**: Administrator
-  createdAt:
-    type: string
-    format: date-time
-    description: Time of creation
-  updatedAt:
-    type: string
-    format: date-time
-    description: Time of the most recent change to the user
-  _links:
-    type: object
+allOf:
+  - $ref: './principal_model.yml'
+  - type: object
     required:
-      - self
-      - memberships
-      - showUser
+      - _type
+      - avatar
     properties:
-      self:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              This user
-
-              **Resource**: User
-      memberships:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              Link to collection of all the user's memberships. The list will only include the memberships in projects in which the requesting user has the necessary permissions.
-
-              **Resource**: MemberCollection
-
-              # Conditions
-
-              **Permission**: view members or manage members in any project
-      showUser:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: Link to the OpenProject user page (HTML)
-      updateImmediately:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              Updates the user's attributes.
-
-              # Conditions
-
-              **Permission**: Administrator, manage_user global permission
-      lock:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              Restrict the user from logging in and performing any actions
-
-              # Conditions
-
-              not locked; **Permission**: Administrator
-      unlock:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              Allow a locked user to login and act again
-
-              # Conditions
-
-              locked; **Permission**: Administrator
-      delete:
-        allOf:
-          - "$ref": "./link.yml"
-          - description: |-
-              Permanently remove a user from the instance
-
-              # Conditions
-
-              **Permission**: Administrator, self-delete
-
-example:
-  _type: User
-  id: 1
-  name: John Sheppard
-  login: j.sheppard
-  firstName: John
-  lastName: Sheppard
-  email: shep@mail.com
-  admin: true
-  avatar: https://example.org/users/1/avatar
-  status: active
-  identityUrl: null,
-  language: en
-  createdAt: '2014-05-21T08:51:20.396Z'
-  updatedAt: '2014-05-21T08:51:20.396Z'
-  _links:
-    self:
-      href: '/api/v3/users/1'
-      title: John Sheppard
-    memberships:
-      href: /api/v3/memberships?filters=%5B%7B%22principal%22%3A%7B%22operator%22%3A%22%3D%22%2C%22values%22%3A%5B%221%22%5D%7D%7D%5D,
-      title: Members
-    showUser:
-      href: '/users/1'
-      type: text/html
-    lock:
-      href: '/api/v3/users/1/lock'
-      title: Set lock on John Sheppard
-      method: post
-    updateImmediately:
-      href: '/api/v3/users/1'
-      title: update John Sheppard
-      method: patch
-    delete:
-      href: '/api/v3/users/1'
-      title: delete John Sheppard
-    method: delete
+      _type:
+        type: string
+        enum:
+          - User
+      avatar:
+        type: string
+        format: uri
+        description: URL to user's avatar
+      login:
+        type: string
+        description: |-
+          The user's login name
+    
+          # Conditions
+    
+          - User is self, or `create_user` or `manage_user` permission globally
+        maxLength: 256
+      firstName:
+        type: string
+        description: |-
+          The user's first name
+    
+          # Conditions
+    
+          - User is self, or `create_user` or `manage_user` permission globally
+        maxLength: 30
+      lastName:
+        type: string
+        description: |-
+          The user's last name
+    
+          # Conditions
+    
+          - User is self, or `create_user` or `manage_user` permission globally
+        maxLength: 30
+      email:
+        type: string
+        description: |-
+          The user's email address
+    
+          # Conditions
+    
+          - E-Mail address not hidden
+          - User is not a new record
+          - User is self, or `create_user` or `manage_user` permission globally
+        maxLength: 60
+      admin:
+        type: boolean
+        description: |-
+          Flag indicating whether or not the user is an admin
+    
+          # Conditions
+    
+          - `admin`
+      status:
+        type: string
+        description: |-
+          The current activation status of the user.
+          
+          # Conditions
+
+          - User is self, or `create_user` or `manage_user` permission globally
+      language:
+        type: string
+        description: |-
+          User's language | ISO 639-1 format
+    
+          # Conditions
+    
+          - User is self, or `create_user` or `manage_user` permission globally
+      identityUrl:
+        type:
+          - 'string'
+          - 'null'
+        description: |-
+          User's identity_url for OmniAuth authentication.
+    
+          # Conditions
+    
+          - User is self, or `create_user` or `manage_user` permission globally
+      createdAt:
+        type: string
+        format: date-time
+        description: Time of creation
+      updatedAt:
+        type: string
+        format: date-time
+        description: Time of the most recent change to the user
+      _links:
+        type: object
+        properties:
+          showUser:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  A relative path to show the user in the web application.
+
+                  # Condition
+
+                  - User is not a new record
+                  - User is not `locked`
+          updateImmediately:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  A link to update the user resource.
+    
+                  # Conditions
+                  
+                  - `admin`
+          lock:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  Restrict the user from logging in and performing any actions.
+    
+                  # Conditions
+    
+                  - User is not locked
+                  - `admin`
+          unlock:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  Allow a locked user to login and act again.
+    
+                  # Conditions
+                  
+                  - User is not locked
+                  - `admin`
+          delete:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  Permanently remove a user from the instance
+    
+                  # Conditions
+    
+                  either:
+                    - `admin`
+                    - Setting `users_deletable_by_admin` is set
+                  or:
+                    - User is self
+                    - Setting `users_deletable_by_self` is set
+          authSource:
+            allOf:
+              - $ref: './link.yml'
+              - description: |-
+                  Permanently remove a user from the instance
+    
+                  # Conditions
+                  
+                  - LDAP authentication configured
+                  - `admin`
diff --git a/docs/api/apiv3/openapi-spec.yml b/docs/api/apiv3/openapi-spec.yml
index a5012089fafe..30ae39bbb872 100644
--- a/docs/api/apiv3/openapi-spec.yml
+++ b/docs/api/apiv3/openapi-spec.yml
@@ -256,6 +256,10 @@ paths:
     "$ref": "./paths/oauth_application.yml"
   "/api/v3/oauth_client_credentials/{id}":
     "$ref": "./paths/oauth_client_credentials.yml"
+  "/api/v3/placeholder_users":
+    "$ref": "./paths/placeholder_users.yml"
+  "/api/v3/placeholder_users/{id}":
+    "$ref": "./paths/placeholder_user.yml"
   "/api/v3/posts/{id}":
     "$ref": "./paths/post.yml"
   "/api/v3/posts/{id}/attachments":
@@ -475,6 +479,8 @@ components:
       $ref: './components/examples/grid-simple-patch-model.yml'
     GridSimpleResponse:
       $ref: './components/examples/grid-simple-response.yml'
+    GroupResponse:
+      $ref: './components/examples/group-response.yml'
     MembershipCreateRequestCustomMessage:
       $ref: './components/examples/membership-create-request-custom-message.yml'
     MembershipCreateRequestGlobalRole:
@@ -495,6 +501,8 @@ components:
       $ref: './components/examples/mentioned_notification.yml'
     NotificationCollection:
       $ref: './components/examples/notification_collection.yml'
+    PlaceholderUserResponse:
+      $ref: './components/examples/placeholder-user-response.yml'
     Project:
       $ref: './components/examples/project.yml'
     ProjectBody:
@@ -511,6 +519,8 @@ components:
       $ref: './components/examples/status_collection.yml'
     StoragesSimpleCollectionModel:
       $ref: './components/examples/storages-simple-collection-response.yml'
+    UserResponse:
+      $ref: './components/examples/user-response.yml'
     ValuesPropertyStartDateSchema:
       $ref: './components/examples/values_property_start_date_schema.yml'
     ValuesPropertyDueDateSchema:
@@ -669,12 +679,20 @@ components:
       "$ref": "./components/schemas/oauth_client_credentials_write_model.yml"
     PaginatedCollectionModel:
       "$ref": "./components/schemas/paginated_collection_model.yml"
+    PlaceholderUserCollectionModel:
+      "$ref": "./components/schemas/placeholder_user_collection_model.yml"
+    PlaceholderUserCreateModel:
+      "$ref": "./components/schemas/placeholder_user_create_model.yml"
+    PlaceholderUserModel:
+      "$ref": "./components/schemas/placeholder_user_model.yml"
     Plain_TextModel:
       "$ref": "./components/schemas/plain_text_model.yml"
     PostModel:
       "$ref": "./components/schemas/post_model.yml"
-    PrincipalsModel:
-      "$ref": "./components/schemas/principals_model.yml"
+    PrincipalCollectionModel:
+      "$ref": "./components/schemas/principal_collection_model.yml"
+    PrincipalModel:
+      "$ref": "./components/schemas/principal_model.yml"
     PrioritiesModel:
       "$ref": "./components/schemas/priorities_model.yml"
     PriorityModel:
diff --git a/docs/api/apiv3/paths/group.yml b/docs/api/apiv3/paths/group.yml
index dae8e3c6988d..f45dd4465fb3 100644
--- a/docs/api/apiv3/paths/group.yml
+++ b/docs/api/apiv3/paths/group.yml
@@ -17,7 +17,7 @@ delete:
   responses:
     '202':
       description: |-
-        Returned if the group was successfully deleted
+        Returned if the group was marked for deletion.
 
         Note that the response body is empty as of now. In future versions of the API a body
         *might* be returned, indicating the progress of deletion.
@@ -79,6 +79,9 @@ get:
         application/hal+json:
           schema:
             $ref: '../components/schemas/group_model.yml'
+          examples:
+            'group response':
+              $ref: '../components/examples/group-response.yml'
     '404':
       description: |-
         Returned if the group does not exist or if the API user does not have permission to view them.
diff --git a/docs/api/apiv3/paths/placeholder_user.yml b/docs/api/apiv3/paths/placeholder_user.yml
new file mode 100644
index 000000000000..f4609c601da3
--- /dev/null
+++ b/docs/api/apiv3/paths/placeholder_user.yml
@@ -0,0 +1,161 @@
+# /api/v3/placeholder_users/{id}
+---
+delete:
+  summary: Delete placeholder user
+  operationId: delete_placeholder_user
+  description: Set the specified placeholder user to deleted status.
+  tags:
+    - Principals
+  parameters:
+    - description: Placeholder user id
+      example: '1'
+      in: path
+      name: id
+      required: true
+      schema:
+        type: integer
+  responses:
+    '202':
+      description: |-
+        Returned if the group was marked for deletion.
+
+        Note that the response body is empty as of now. In future versions of the API a body
+        *might* be returned, indicating the progress of deletion.
+    '403':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:MissingPermission
+            message: You are not allowed to delete the account of this user.
+      description: |-
+        Returned if the client does not have sufficient permissions.
+
+        **Required permission:** `manage_placeholder_users`
+    '404':
+      description: Returned if the placeholder user does not exist.
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:NotFound
+            message: The specified placeholder user does not exist.
+
+get:
+  summary: View placeholder user
+  operationId: view_placeholder_user
+  description: Return the placeholder user resource.
+  tags:
+    - Principals
+  parameters:
+    - description: The placeholder user id
+      example: '1'
+      in: path
+      name: id
+      required: true
+      schema:
+        type: string
+  responses:
+    '200':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/placeholder_user_model.yml'
+          examples:
+            'placeholder user response':
+              $ref: '../components/examples/placeholder-user-response.yml'
+      description: OK
+    '404':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:NotFound
+            message: The specified placeholder user does not exist or you do not have permission to view them.
+      description: |-
+        Returned if the user does not exist or if the API user does not have permission to view them.
+
+        **Required permission**: `manage_placeholder_users`
+
+patch:
+  summary: Update placeholder user
+  operationId: update_placeholder_user
+  tags:
+    - Principals
+  description: |-
+    Updates the placeholder user's writable attributes.
+    When calling this endpoint the client provides a single object, containing at least the properties and links
+    that are required, in the body.
+  parameters:
+    - description: Placeholder user id
+      example: '1'
+      in: path
+      name: id
+      required: true
+      schema:
+        type: integer
+  requestBody:
+    content:
+      application/json:
+        schema:
+          $ref: '../components/schemas/placeholder_user_create_model.yml'
+  responses:
+    '200':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/placeholder_user_model.yml'
+      description: OK
+    '400':
+      $ref: "../components/responses/invalid_request_body.yml"
+    '403':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:MissingPermission
+            message: You are not allowed to update the account of this user.
+      description: |-
+        Returned if the client does not have sufficient permissions.
+
+        **Required permission**: `manage_placeholder_users`
+    '404':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+              _type: Error
+              errorIdentifier: urn:openproject-org:api:v3:errors:NotFound
+              message: The specified placeholder user does not exist.
+      description: |-
+        Returned if the placeholder user does not exist.
+    '406':
+      $ref: "../components/responses/missing_content_type.yml"
+    '415':
+      $ref: "../components/responses/unsupported_media_type.yml"
+    '422':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _embedded:
+              details:
+                attribute: name
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:PropertyConstraintViolation
+            message: Name has already been taken.
+      description: |-
+        Returned if:
+
+        - the client tries to modify a read-only property (`PropertyIsReadOnly`)
+        - a constraint for a property was violated (`PropertyConstraintViolation`)
diff --git a/docs/api/apiv3/paths/placeholder_users.yml b/docs/api/apiv3/paths/placeholder_users.yml
new file mode 100644
index 000000000000..39bb3acccd10
--- /dev/null
+++ b/docs/api/apiv3/paths/placeholder_users.yml
@@ -0,0 +1,108 @@
+# /api/v3/placeholder_users
+---
+get:
+  summary: List placehoder users
+  operationId: list_placeholder_users
+  tags:
+    - Principals
+  description: |-
+    List all placeholder users. This can only be accessed if the requesting user has the global permission
+    `manage_placeholder_user` or `manage_members` in any project.
+  parameters:
+    - name: filters
+      description: |-
+        JSON specifying filter conditions.
+        Accepts the same format as returned by the [queries](https://www.openproject.org/docs/api/endpoints/queries/) endpoint.
+        Currently supported filters are:
+        
+        - name: filters placeholder users by the name.
+        - group: filters placeholder by the group it is contained in.
+        - status: filters placeholder by the status it has.
+      in: query
+      required: false
+      schema:
+        type: string
+      example: '[{ "name": { "operator": "~", "values": ["Darth"] } }]'
+    - name: select
+      description: Comma separated list of properties to include.
+      in: query
+      required: false
+      schema:
+        type: string
+      example: 'total,elements/name,elements/self,self'
+  responses:
+    '200':
+      description: OK
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/principal_collection_model.yml'
+    '400':
+      description: Returned if the client sends invalid request parameters e.g. filters
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:InvalidQuery
+            message: Filters Invalid filter does not exist.
+
+post:
+  summary: Create placeholder user
+  operationId: create_placeholder_user
+  tags:
+    - Principals
+  description: |-
+    Creates a new placeholder user. Only administrators and users with `manage_placeholder_user` global permission are
+    allowed to do so. When calling this endpoint the client provides a single object, containing at least the
+    properties and links that are required, in the body.
+  requestBody:
+    content:
+      application/json:
+        schema:
+          $ref: '../components/schemas/placeholder_user_create_model.yml'
+  responses:
+    '201':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/placeholder_user_model.yml'
+      description: Created
+    '400':
+      $ref: '../components/responses/invalid_request_body.yml'
+    '403':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:MissingPermission
+            message: You are not allowed to create new placeholder users.
+      description: |-
+        Returned if the client does not have sufficient permissions.
+
+        **Required permission:** Administrator
+    '406':
+      $ref: '../components/responses/missing_content_type.yml'
+    '415':
+      $ref: '../components/responses/unsupported_media_type.yml'
+    '422':
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _embedded:
+              details:
+                attribute: name
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:PropertyConstraintViolation
+            message: Name has already been taken.
+      description: |-
+        Returned if:
+
+        * a constraint for a property was violated (`PropertyConstraintViolation`)
+
+  
diff --git a/docs/api/apiv3/paths/principals.yml b/docs/api/apiv3/paths/principals.yml
index 1cdd47be7702..bc4c25c856aa 100644
--- a/docs/api/apiv3/paths/principals.yml
+++ b/docs/api/apiv3/paths/principals.yml
@@ -1,141 +1,52 @@
 # /api/v3/principals
 ---
 get:
+  summary: List principals
+  operationId: list_principals
+  tags:
+    - Principals
+  description: |-
+    List all principals. The client can choose to filter the principals similar to how work packages are filtered. In
+    addition to the provided filters, the server will reduce the result set to only contain principals who are members
+    in projects the client is allowed to see.
   parameters:
-  - description: |-
-      JSON specifying filter conditions.
-      Accepts the same format as returned by the [queries](https://www.openproject.org/docs/api/endpoints/queries/) endpoint.
-      Currently supported filters are:
-
-      + type: filters principals by their type (*User*, *Group*, *PlaceholderUser*).
-
-      + member: filters principals by the projects they are members in.
-
-      + name: filters principals by the user or group name.
-
-      + any_name_attribute: filters principals by the user or group first- and last name, email or login.
-
-      + status: filters principals by their status number (active = *1*, registered = *2*, locked = *3*, invited = *4*)
-    example: '[{ "type": { "operator": "=", "values": ["User"] } }]'
-    in: query
-    name: filters
-    required: false
-    schema:
-      type: string
-  - description: |-
-      Comma separated list of properties to include.
-    example: 'total,elements/name,elements/self,self'
-    in: query
-    name: select
-    required: false
-    schema:
-      type: string
+    - name: filters
+      description: |-
+        JSON specifying filter conditions.
+        Accepts the same format as returned by the [queries](https://www.openproject.org/docs/api/endpoints/queries/) endpoint.
+        Currently supported filters are:
+        
+        - type: filters principals by their type (*User*, *Group*, *PlaceholderUser*).
+        - member: filters principals by the projects they are members in.
+        - name: filters principals by the user or group name.
+        - any_name_attribute: filters principals by the user or group first- and last name, email or login.
+        - status: filters principals by their status number (active = *1*, registered = *2*, locked = *3*, invited = *4*)
+      in: query
+      required: false
+      schema:
+        type: string
+      example: '[{ "type": { "operator": "=", "values": ["User"] } }]'
+    - name: select
+      description: Comma separated list of properties to include.
+      in: query
+      required: false
+      schema:
+        type: string
+      example: 'total,elements/name,elements/self,self'
   responses:
     '200':
+      description: OK
       content:
         application/hal+json:
-          examples:
-            response:
-              value:
-                _embedded:
-                  elements:
-                  - _links:
-                      delete:
-                        href: "/api/v3/users/4"
-                        method: delete
-                        title: Delete Eliza92778
-                      lock:
-                        href: "/api/v3/users/4/lock"
-                        method: post
-                        title: Set lock on Eliza92778
-                      self:
-                        href: "/api/v3/users/4"
-                        title: Danika O'Keefe
-                      showUser:
-                        href: "/users/4"
-                        type: text/html
-                      updateImmediately:
-                        href: "/api/v3/users/4"
-                        method: patch
-                        title: Update Eliza92778
-                    _type: User
-                    admin: false
-                    avatar: https://example.org/users/4/avatar
-                    createdAt: '2015-03-20T12:57:02.901Z'
-                    email: jackie@dicki.org
-                    firstName: Danika
-                    id: 4
-                    identityUrl:
-                    lastName: O'Keefe
-                    login: Eliza92778
-                    name: Danika O'Keefe
-                    status: active
-                    updatedAt: '2015-06-16T15:28:14.565Z'
-                  - _links:
-                      delete:
-                        href: "/api/v3/users/2"
-                        method: delete
-                        title: Delete Sebastian9686
-                      lock:
-                        href: "/api/v3/users/2/lock"
-                        method: post
-                        title: Set lock on Sebastian9686
-                      self:
-                        href: "/api/v3/users/2"
-                        title: Peggie Feeney
-                      showUser:
-                        href: "/users/2"
-                        type: text/html
-                      updateImmediately:
-                        href: "/api/v3/users/2"
-                        method: patch
-                        title: Update Sebastian9686
-                    _type: User
-                    admin: false
-                    avatar: https://example.org/users/4/avatar
-                    createdAt: '2015-03-20T12:56:55.578Z'
-                    email:
-                    firstName: Peggie
-                    id: 2
-                    identityUrl:
-                    lastName: Feeney
-                    login: Sebastian9686
-                    name: Peggie Feeney
-                    status: active
-                    updatedAt: '2015-03-20T12:56:55.254Z'
-                  - _links:
-                      self:
-                        href: "/api/v3/groups/9"
-                        title: The group
-                    _type: Group
-                    createdAt: '2015-09-23T11:06:36.231Z'
-                    id: 9
-                    name: The group
-                    updatedAt: '2015-09-23T11:06:36.231Z'
-                  - _links:
-                      self:
-                        href: "/api/v3/placeholder_users/29"
-                        title: UX Designer
-                    _type: PlaceholderUser
-                    createdAt: '2018-09-23T11:06:36.231Z'
-                    id: 29
-                    name: UX Designer
-                    updatedAt: '2019-10-23T11:06:36.231Z'
-                _links:
-                  self:
-                    href: "/api/v3/principals"
-                _type: Collection
-                count: 4
-                total: 4
           schema:
-            "$ref": "../components/schemas/principals_model.yml"
-      description: OK
-      headers: {}
-  tags:
-  - Principals
-  description: List all principals. The client can choose to filter the principals
-    similar to how work packages are filtered. In addition to the provided filters,
-    the server will reduce the result set to only contain principals who are members
-    in projects the client is allowed to see.
-  operationId: List_principals
-  summary: List principals
+            $ref: '../components/schemas/principal_collection_model.yml'
+    '400':
+      description: Returned if the client sends invalid request parameters e.g. filters
+      content:
+        application/hal+json:
+          schema:
+            $ref: '../components/schemas/error_response.yml'
+          example:
+            _type: Error
+            errorIdentifier: urn:openproject-org:api:v3:errors:InvalidQuery
+            message: Filters Invalid filter does not exist.
diff --git a/docs/api/apiv3/paths/user.yml b/docs/api/apiv3/paths/user.yml
index cd996fde062e..b7e22c2c2455 100644
--- a/docs/api/apiv3/paths/user.yml
+++ b/docs/api/apiv3/paths/user.yml
@@ -6,6 +6,7 @@ delete:
   description: Permanently deletes the specified user account.
   tags:
     - Users
+    - Principals
   parameters:
     - description: User id
       example: '1'
@@ -51,6 +52,7 @@ get:
   description: ''
   tags:
     - Users
+    - Principals
   parameters:
     - description: User id. Use `me` to reference current user, if any.
       example: '1'
@@ -65,6 +67,9 @@ get:
         application/hal+json:
           schema:
             $ref: '../components/schemas/user_model.yml'
+          examples:
+            'user response':
+              $ref: '../components/examples/user-response.yml'
       description: OK
     '404':
       content:
@@ -85,6 +90,7 @@ patch:
   operationId: update_user
   tags:
     - Users
+    - Principals
   description: |-
     Updates the user's writable attributes.
     When calling this endpoint the client provides a single object, containing at least the properties and links that are required, in the body.
diff --git a/docs/api/apiv3/paths/users.yml b/docs/api/apiv3/paths/users.yml
index b9036967c48b..d31515008e28 100644
--- a/docs/api/apiv3/paths/users.yml
+++ b/docs/api/apiv3/paths/users.yml
@@ -3,9 +3,15 @@
 get:
   summary: List Users
   operationId: list_Users
-  description: "Lists users. Only administrators or users with any of the following can access this resource: 'manage_members', 'manage_user', 'share_work_packages'."
+  description: |- 
+    Lists users. Only administrators or users with any of the following can access this resource:
+    
+    - `manage_members`
+    - `manage_user`
+    - `share_work_packages`
   tags:
     - Users
+    - Principals
   parameters:
     - description: Page number inside the requested collection.
       example: '25'
@@ -87,6 +93,7 @@ post:
   operationId: create_user
   tags:
     - Users
+    - Principals
   description: |-
     Creates a new user. Only administrators and users with manage_user global permission are allowed to do so.
     When calling this endpoint the client provides a single object, containing at least the properties and links that are required, in the body.
diff --git a/lib/api/v3/placeholder_users/placeholder_user_representer.rb b/lib/api/v3/placeholder_users/placeholder_user_representer.rb
index 758b3f662ec9..f783a96eda84 100644
--- a/lib/api/v3/placeholder_users/placeholder_user_representer.rb
+++ b/lib/api/v3/placeholder_users/placeholder_user_representer.rb
@@ -55,10 +55,21 @@ class PlaceholderUserRepresenter < ::API::V3::Principals::PrincipalRepresenter
           }
         end
 
+        property :status,
+                 getter: ->(*) { represented.status },
+                 setter: ->(fragment:, represented:, **) { represented.status = User.statuses[fragment.to_sym] },
+                 exec_context: :decorator,
+                 render_nil: true,
+                 cache_if: -> { current_user_can_manage? }
+
         def _type
           'PlaceholderUser'
         end
 
+        def current_user_can_see_date_properties?
+          current_user_can_manage?
+        end
+
         def current_user_can_manage?
           current_user&.allowed_globally?(:manage_placeholder_user)
         end
diff --git a/lib/api/v3/principals/principal_representer.rb b/lib/api/v3/principals/principal_representer.rb
index 33813ee011b6..7a9c07b6a36d 100644
--- a/lib/api/v3/principals/principal_representer.rb
+++ b/lib/api/v3/principals/principal_representer.rb
@@ -52,7 +52,7 @@ class PrincipalRepresenter < ::API::Decorators::Single
 
           {
             href: api_v3_paths.path_for(:memberships, filters:),
-            title: I18n.t(:label_member_plural)
+            title: I18n.t(:label_membership_plural)
           }
         end
 
@@ -63,10 +63,14 @@ class PrincipalRepresenter < ::API::Decorators::Single
                  render_nil: true
 
         date_time_property :created_at,
-                           cache_if: -> { current_user_is_admin_or_self }
+                           cache_if: -> { current_user_can_see_date_properties? }
 
         date_time_property :updated_at,
-                           cache_if: -> { current_user_is_admin_or_self }
+                           cache_if: -> { current_user_can_see_date_properties? }
+
+        def current_user_can_see_date_properties?
+          current_user_is_admin_or_self
+        end
 
         def current_user_is_admin_or_self
           current_user_is_admin? || current_user_is_self?
diff --git a/spec/lib/api/v3/placeholder_users/placeholder_user_representer_rendering_spec.rb b/spec/lib/api/v3/placeholder_users/placeholder_user_representer_rendering_spec.rb
index 122056d9eb1c..030fa8d2c30c 100644
--- a/spec/lib/api/v3/placeholder_users/placeholder_user_representer_rendering_spec.rb
+++ b/spec/lib/api/v3/placeholder_users/placeholder_user_representer_rendering_spec.rb
@@ -59,7 +59,7 @@
   end
 
   describe '_links' do
-    context 'self' do
+    describe 'self' do
       it_behaves_like 'has a titled link' do
         let(:link) { 'self' }
         let(:href) { api_v3_paths.placeholder_user placeholder_user.id }
@@ -67,19 +67,19 @@
       end
     end
 
-    context 'showUser' do
+    describe 'showUser' do
       it_behaves_like 'has an untitled link' do
         let(:link) { 'showUser' }
         let(:href) { "/placeholder_users/#{placeholder_user.id}" }
       end
     end
 
-    context 'delete' do
+    describe 'delete' do
       it_behaves_like 'has no link' do
         let(:link) { 'delete' }
       end
 
-      context 'when user allowed to manage' do
+      context 'if user is allowed to manage' do
         let(:global_permissions) { [:manage_placeholder_user] }
 
         it_behaves_like 'has a titled link' do
@@ -91,7 +91,7 @@
       end
     end
 
-    context 'updateImmediately' do
+    describe 'updateImmediately' do
       it_behaves_like 'has no link' do
         let(:link) { 'updateImmediately' }
       end
@@ -108,28 +108,28 @@
       end
     end
 
-    context 'memberships' do
+    describe 'memberships' do
       it_behaves_like 'has no link' do
         let(:link) { 'memberships' }
       end
 
-      context 'user allowed to see members' do
+      context 'if user is allowed to see members' do
         let(:project_permissions) { [:view_members] }
 
         it_behaves_like 'has a titled link' do
           let(:link) { 'memberships' }
           let(:href) { memberships_path }
-          let(:title) { I18n.t(:label_member_plural) }
+          let(:title) { I18n.t(:label_membership_plural) }
         end
       end
 
-      context 'user allowed to manage members' do
+      context 'if user is allowed to manage members' do
         let(:project_permissions) { [:manage_members] }
 
         it_behaves_like 'has a titled link' do
           let(:link) { 'memberships' }
           let(:href) { memberships_path }
-          let(:title) { I18n.t(:label_member_plural) }
+          let(:title) { I18n.t(:label_membership_plural) }
         end
       end
     end
@@ -140,15 +140,15 @@
       let(:value) { 'PlaceholderUser' }
     end
 
-    context 'as regular user' do
-      it_behaves_like 'property', :id do
-        let(:value) { placeholder_user.id }
-      end
+    it_behaves_like 'property', :id do
+      let(:value) { placeholder_user.id }
+    end
 
-      it_behaves_like 'property', :name do
-        let(:value) { placeholder_user.name }
-      end
+    it_behaves_like 'property', :name do
+      let(:value) { placeholder_user.name }
+    end
 
+    context 'as regular user' do
       it 'hides the updatedAt property' do
         expect(subject).not_to have_json_path('updatedAt')
       end
@@ -158,15 +158,11 @@
       end
     end
 
-    context 'as admin' do
-      let(:current_user) { build_stubbed(:admin) }
+    context 'if user is allowed to manage placeholder users' do
+      let(:global_permissions) { [:manage_placeholder_user] }
 
-      it_behaves_like 'property', :id do
-        let(:value) { placeholder_user.id }
-      end
-
-      it_behaves_like 'property', :name do
-        let(:value) { placeholder_user.name }
+      it_behaves_like 'property', :status do
+        let(:value) { 'active' }
       end
 
       it_behaves_like 'datetime property', :createdAt do
@@ -181,12 +177,15 @@
 
   describe 'caching' do
     it 'is based on the representer\'s cache_key' do
-      expect(OpenProject::Cache)
+      allow(OpenProject::Cache)
         .to receive(:fetch)
-              .with(representer.json_cache_key)
               .and_call_original
 
       representer.to_json
+
+      expect(OpenProject::Cache)
+        .to have_received(:fetch)
+              .with(representer.json_cache_key)
     end
 
     describe '#json_cache_key' do
@@ -205,7 +204,7 @@
       end
 
       it 'changes when the placeholder is updated' do
-        placeholder_user.updated_at = Time.now + 20.seconds
+        placeholder_user.updated_at = 20.seconds.from_now
 
         expect(representer.json_cache_key)
           .not_to eql former_cache_key
diff --git a/spec/lib/api/v3/users/user_representer_spec.rb b/spec/lib/api/v3/users/user_representer_spec.rb
index 877052a520a5..fe12cac792ad 100644
--- a/spec/lib/api/v3/users/user_representer_spec.rb
+++ b/spec/lib/api/v3/users/user_representer_spec.rb
@@ -36,7 +36,7 @@
 
   include API::V3::Utilities::PathHelper
 
-  context 'generation' do
+  describe 'generation' do
     subject(:generated) { representer.to_json }
 
     it do
@@ -114,13 +114,13 @@
         end
       end
 
-      context 'user shows his E-Mail address' do
+      context 'if user shows his E-Mail address' do
         let(:preference) { build(:user_preference, hide_mail: false) }
 
         it_behaves_like 'shows the users E-Mail address'
       end
 
-      context 'user hides his E-Mail address' do
+      context 'if user hides his E-Mail address' do
         let(:preference) { build(:user_preference, hide_mail: true) }
 
         it 'does not render the users E-Mail address' do
@@ -156,7 +156,7 @@
         expect(subject).to have_json_path('_links/self/href')
       end
 
-      context 'showUser' do
+      describe 'showUser' do
         it_behaves_like 'has an untitled link' do
           let(:link) { 'showUser' }
           let(:href) { "/users/#{user.id}" }
@@ -197,8 +197,8 @@
         context 'when deletion is allowed' do
           before do
             allow(Users::DeleteContract).to receive(:deletion_allowed?)
-                                             .with(user, current_user)
-                                             .and_return(true)
+                                              .with(user, current_user)
+                                              .and_return(true)
           end
 
           it 'links to delete' do
@@ -210,8 +210,8 @@
       context 'when deletion is allowed' do
         before do
           allow(Users::DeleteContract).to receive(:deletion_allowed?)
-            .with(user, current_user)
-            .and_return(true)
+                                            .with(user, current_user)
+                                            .and_return(true)
         end
 
         it 'links to delete' do
@@ -222,8 +222,8 @@
       context 'when deletion is not allowed' do
         before do
           allow(Users::DeleteContract).to receive(:deletion_allowed?)
-            .with(user, current_user)
-            .and_return(false)
+                                            .with(user, current_user)
+                                            .and_return(false)
         end
 
         it 'does not link to delete' do
@@ -252,7 +252,7 @@
 
           it_behaves_like 'has a titled link' do
             let(:link) { 'memberships' }
-            let(:title) { I18n.t(:label_member_plural) }
+            let(:title) { I18n.t(:label_membership_plural) }
           end
         end
 
@@ -261,7 +261,7 @@
 
           it_behaves_like 'has a titled link' do
             let(:link) { 'memberships' }
-            let(:title) { I18n.t(:label_member_plural) }
+            let(:title) { I18n.t(:label_membership_plural) }
           end
         end
 
@@ -277,12 +277,15 @@
 
     describe 'caching' do
       it 'is based on the representer\'s cache_key' do
-        expect(OpenProject::Cache)
+        allow(OpenProject::Cache)
           .to receive(:fetch)
-          .with(representer.json_cache_key)
-          .and_call_original
+                .and_call_original
 
         representer.to_json
+
+        expect(OpenProject::Cache)
+          .to have_received(:fetch)
+                .with(representer.json_cache_key)
       end
 
       describe '#json_cache_key' do
@@ -308,7 +311,7 @@
         end
 
         it 'changes when the user is updated' do
-          user.updated_at = Time.now + 20.seconds
+          user.updated_at = 20.seconds.from_now
 
           expect(representer.json_cache_key)
             .not_to eql former_cache_key
diff --git a/spec/requests/api/v3/placeholder_users/delete_resource_examples.rb b/spec/requests/api/v3/placeholder_users/delete_resource_examples.rb
index 37e5f64fa4b4..41478c989d39 100644
--- a/spec/requests/api/v3/placeholder_users/delete_resource_examples.rb
+++ b/spec/requests/api/v3/placeholder_users/delete_resource_examples.rb
@@ -51,6 +51,6 @@
   end
 
   it 'does not delete the user' do
-    expect(PlaceholderUser.exists?(placeholder.id)).to be_truthy
+    expect(PlaceholderUser).to exist(placeholder.id)
   end
 end