diff --git a/docs/extensions/components/preview-extension.component.md b/docs/extensions/components/preview-extension.component.md
index a90d7313ee..4b0f275ff5 100644
--- a/docs/extensions/components/preview-extension.component.md
+++ b/docs/extensions/components/preview-extension.component.md
@@ -2,12 +2,12 @@
 Title: Preview Extension Component
 Added: v3.1.0
 Status: Experimental
-Last reviewed: 2018-04-12
+Last reviewed: 2019-03-15
 ---
 
 # [Preview Extension component](../../../lib/extensions/src/lib/components/viewer/preview-extension.component.ts "Defined in preview-extension.component.ts")
 
-Displays dynamically-loaded extension components.
+Supports dynamically-loaded viewer preview extensions.
 
 See the [ACA monaco extension](https://github.com/eromano/aca-monaco-extension) for
 an example of a real working viewer extension project.
@@ -18,16 +18,16 @@ an example of a real working viewer extension project.
 
 | Name | Type | Default value | Description |
 | ---- | ---- | ------------- | ----------- |
-| extension | `string` |  |  |
-| id | `string` |  |  |
-| node | [`Node`](https://github.com/Alfresco/alfresco-js-api/blob/development/src/api/content-rest-api/docs/Node.md) |  | of the content to display |
-| url | `string` |  | URL Of the content in the repository |
+| extension | `string` |  | File extension (.jpg, .png, etc) for the viewer. |
+| id | `string` |  | ID string of the component to preview. |
+| node | [`Node`](https://github.com/Alfresco/alfresco-js-api/blob/development/src/api/content-rest-api/docs/Node.md) |  | [Node](https://github.com/Alfresco/alfresco-js-api/blob/development/src/api/content-rest-api/docs/Node.md) containing the content to display. |
+| url | `string` |  | URL of the content in the repository. |
 
 ## Details
 
-If you want create your custom extension viewer you need to create the following files in a separate project:
+To create your custom extension viewer you need to create the following files in a separate project:
 
-The Module needs to know which is the Id of your extension:
+The Module needs to declare the ID of your extension:
 
 ```ts
 export class YourExtensionViewerModule {
@@ -39,7 +39,8 @@ export class YourExtensionViewerModule {
 }
 ```
 
-Your [viewer component](../../core/components/viewer.component.md) extension business logic:
+Your [viewer component](../../core/components/viewer.component.md) extension contains
+the business logic:
 
 ```ts
 import { Node } from '@alfresco/js-api';
@@ -66,13 +67,15 @@ export class YourExtensionViewerComponent implements ViewerExtensionInterface {
 }
 ```
 
-Your [viewer component](../../core/components/viewer.component.md) template:
+The [viewer component](../../core/components/viewer.component.md)
+also needs an HTML template (which is referenced by the `templateUrl` property
+in the `@Component` decorator of the component class above):
 
 ```HTML
 <div> This is your custom extension viewer template</div>
 ```
 
-Your [viewer component](../../core/components/viewer.component.md) extension.json:
+You also need to provide a [viewer component](../../core/components/viewer.component.md)`extension.json` file containing its details:
 
 ```JSON
 {
@@ -93,6 +96,10 @@ Your [viewer component](../../core/components/viewer.component.md) extension.jso
 }
 ```
 
+See the [App extensions](../../user-guide/app-extensions.md) page for
+further details of how to develop extensions.
+
 ## See also
 
 -   [Extension service](../services/extension.service.md)
+-   [App extensions](../../user-guide/app-extensions.md)
diff --git a/docs/process-services-cloud/components/process-header-cloud.component.md b/docs/process-services-cloud/components/process-header-cloud.component.md
index 3f4e9b2942..5914593f4c 100644
--- a/docs/process-services-cloud/components/process-header-cloud.component.md
+++ b/docs/process-services-cloud/components/process-header-cloud.component.md
@@ -2,7 +2,7 @@
 Title: Process Header Cloud Component
 Added: v3.0.0
 Status: Experimental
-Last reviewed: 2019-03-08
+Last reviewed: 2019-03-15
 ---
 
 # [Process Header Cloud Component](../../../lib/process-services-cloud/src/lib/process/process-header/components/process-header-cloud.component.ts "Defined in process-header-cloud.component.ts")
@@ -32,7 +32,7 @@ Shows all the information related to a process instance.
 ## Details
 
 The component populates an internal array of
-[`CardViewModel`](../../core/components/card-view.component.md) with the information that we want to display.
+[`CardViewModel`](../../core/components/card-view.component.md) with the information to display.
 
 By default all properties are displayed:
 
@@ -49,3 +49,7 @@ However, you can also choose which properties to show using a configuration in `
 ```
 
 With this configuration, only the four listed properties will be shown.
+
+## See also
+
+-   [Process header cloud service](../../process-services-cloud/services/process-header-cloud.service.md)
diff --git a/docs/process-services-cloud/services/process-header-cloud.service.md b/docs/process-services-cloud/services/process-header-cloud.service.md
index fad2158ce6..381fc9a2ae 100644
--- a/docs/process-services-cloud/services/process-header-cloud.service.md
+++ b/docs/process-services-cloud/services/process-header-cloud.service.md
@@ -2,7 +2,7 @@
 Title: Process Header Cloud Service
 Added: v3.0.0
 Status: Experimental
-Last reviewed: 2019-03-08
+Last reviewed: 2019-03-15
 ---
 
 # [Process Header Cloud Service](../../../lib/process-services-cloud/src/lib/process/process-header/services/process-header-cloud.service.ts "Defined in process-header-cloud.service.ts")
@@ -29,3 +29,4 @@ but they use the cloud variants of the classes for return values. See the
 ## See also
 
 -   [Process list Cloud Service](process-list-cloud.service.md)
+-   [Process header cloud component](../../process-services-cloud/components/process-header-cloud.component.md)
diff --git a/lib/extensions/src/lib/components/viewer/preview-extension.component.ts b/lib/extensions/src/lib/components/viewer/preview-extension.component.ts
index 43eedff097..5ad3d189ef 100644
--- a/lib/extensions/src/lib/components/viewer/preview-extension.component.ts
+++ b/lib/extensions/src/lib/components/viewer/preview-extension.component.ts
@@ -39,15 +39,19 @@ export class PreviewExtensionComponent implements OnInit, OnChanges, OnDestroy {
     @ViewChild('content', { read: ViewContainerRef })
     content: ViewContainerRef;
 
+    /** ID string of the component to preview. */
     @Input()
     id: string;
 
+    /** URL of the content in the repository. */
     @Input()
     url: string;
 
+    /** File extension (.jpg, .png, etc) for the viewer. */
     @Input()
     extension: string;
 
+    /** Node containing the content to display. */
     @Input()
     node: Node;