diff --git a/doc/source/admin/interoperable-image-import.rst b/doc/source/admin/interoperable-image-import.rst
index de08b9d6f6..424f527024 100644
--- a/doc/source/admin/interoperable-image-import.rst
+++ b/doc/source/admin/interoperable-image-import.rst
@@ -67,6 +67,63 @@ task-related policies:
    "modify_task": "",
    "tasks_api_access": "role:admin",
 
+Customizing the image import process
+------------------------------------
+
+When a user issues the image-import call, Glance retrieves the staged image
+data, processes it, and saves the result in the backing store.  You can
+customize the nature of this processing by using *plugins*.  Some plugins
+are provided by the Glance project team, you can use third-party plugins,
+or you can write your own.
+
+Technical information
+~~~~~~~~~~~~~~~~~~~~~
+
+The import step of interoperable image import is performed by a `Taskflow`_
+"flow" object.  This object, provided by Glance, will call any plugins you have
+specified in the ``glance-image-import.conf`` file.  The plugins are loaded by
+`Stevedore`_ and must be listed in the entry point registry in the namespace
+``glance.image_import.plugins``.  (If you are using only plugins provided by
+the Glance project team, these are already registered for you.)
+
+A plugin must be written in Python as a `Taskflow "Task" object`_.  The file
+containing this object must be present in the ``glance/async/flows/plugins``
+directory.  The plugin file must contain a ``get_flow`` function that returns a
+Taskflow Task object wrapped in a linear flow.  See the ``no_op`` plugin,
+located at ``glance/async/flows/plugins/no_op.py`` for an example of how to do
+this.
+
+Specifying the plugins to be used
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+First, the plugin code must exist in the directory
+``glance/async/flows/plugins``.  The name of a plugin is the filename (without
+extension) of the file containing the plugin code.  For example, a file named
+``fred_mertz.py`` would contain the plugin ``fred_mertz``.
+
+Second, the plugin must be listed in the entry point list for the
+``glance.image_import.plugins`` namespace.  (If you are using only plugins
+provided with Glance, this will have already been done for you, but it never
+hurts to check.)  The entry point list is in ``setup.cfg``.  Find the section
+with the heading ``[entry_points]`` and look for the line beginning with
+``glance.image_import.plugins =``.  It will be followed by a series of lines
+of the form::
+
+  <plugin-name> = <module-package-name>:get_flow
+
+For example::
+
+  no_op = glance.async.flows.plugins.no_op:get_flow
+
+Make sure any plugin you want to use is included here.
+
+Third, the plugin must be listed in the ``glance-image-import.conf`` file as
+one of the plugin names in the list providing the value for the
+``image_import_plugins`` option.  Plugins are executed in the order they are
+specified in this list.
 
 .. _`Image Import Refactor`: https://specs.openstack.org/openstack/glance-specs/specs/mitaka/approved/image-import/image-import-refactor.html
 .. _`Interoperable Image Import`: https://developer.openstack.org/api-ref/image/v2/index.html#interoperable-image-import
+.. _`Stevedore`: https://docs.openstack.org/stevedore
+.. _`Taskflow`: https://docs.openstack.org/taskflow
+.. _`Taskflow "Task" object`: https://docs.openstack.org/taskflow/latest/user/atoms.html#task