portfolio/tags: Explore tagged content of others

New feature in Mahara 18.10: Explore tagged content
of other people based on their tags. Click a tag and
be taken to a list of content items that have been
tagged with that tag (Bug #1755919).

source/portfolio/tags.rst

@@ -139,3 +139,44 @@ You can edit your tags to correct spelling mistakes or delete a tag.
       The items themselves that were associated with the tag are not deleted though.
 
 #. You can click the *My tags* button to be taken back to the overview page of all your tags and their associated resources.
+
+.. index::
+   single: New in Mahara 18.10; View tagged content of others
+   single: Tagging; View tagged content of others
+
+.. _tagged_content:
+
+|new in Mahara 18.10| View tagged content from others
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can explore the content of another person's portfolio by clicking a tag on their page. By doing so, you get to see a list of all artefacts, blocks, pages, and collections that have been tagged with this tag and to which you have access.
+
+.. note::
+   You can only view tagged content of other people, but not group, institution, or site portfolios.
+
+.. figure:: /images/tagged_content_page.*
+   :alt: Click a tag on the page to view the content to which you have access
+
+   Click a tag on the page to view the content to which you have access
+
+Click a tag underneath the page heading or on any artefact that you can see on the page to be taken to the page where all tagged content is displayed that you can view based on your permissions.
+
+.. figure:: /images/tagged_content_of_others.*
+   :alt: View a list of content items to which you have access
+
+   View a list of content items to which you have access
+
+#. The page heading tells you that you are viewing the content of the portfolio owner.
+
+   .. note::
+      When the portfolio owner shared their portfolio publically or via a secret URL and a person who is not logged in views the page and follows a tag, they can only see content tagged on that particular portfolio but not anywhere else.
+
+#. You see the tag that you selected.
+#. You can filter according to content types.
+
+   .. note::
+      If the portfolio owner shared more than one portfolio with you in which the tag was used, you see that content as well.
+
+#. **Sort**: You can sort the results by name or date.
+#. You see the content item. If it is a page or collection you can click it directly. All tags are mentioned associated with that content item.
+#. If it is an artefact, you see the page title and have a direct link to the artefact. Blocks only point to pages as they do not have artefact details pages.