diff --git a/includes/ingest.form.inc b/includes/ingest.form.inc
index db031dc0..f39d38ff 100644
--- a/includes/ingest.form.inc
+++ b/includes/ingest.form.inc
@@ -26,6 +26,8 @@
  *     be related.
  *   - models: An array of content model PIDs, to which the new object might
  *     subscribe
+ *   - parent: The parent of the child to be ingested. This is needed for XACML
+ *     to correctly apply the parent's POLICY to children.
  *
  * @return array
  *   The form definition of the current step.
@@ -133,6 +135,50 @@ function islandora_ingest_form_get_step(array &$form_state, $step_id = NULL) {
   return NULL;
 }
 
+/**
+ * Gets the next step.
+ *
+ * If the current step is not defined, its assumed to be the first step.
+ *
+ * @param array $form_state
+ *   The Drupal form state.
+ * @param string $step
+ *   The step relative to the result, if not provided the current step is used.
+ *
+ * @return string
+ *   The next step if found, NULL otherwise.
+ */
+function islandora_ingest_form_get_next_step(array &$form_state, array $step = NULL) {
+  $step = isset($step) ? $step : islandora_ingest_form_get_step($form_state);
+  $next_step_id = islandora_ingest_form_get_next_step_id($form_state, $step['id']);
+  if ($next_step_id) {
+    return islandora_ingest_form_get_step($form_state, $next_step_id);
+  }
+  return NULL;
+}
+
+/**
+ * Gets the previous step.
+ *
+ * If the current step is not defined, its assumed to be the first step.
+ *
+ * @param array $form_state
+ *   The Drupal form state.
+ * @param string $step
+ *   The step relative to the result, if not provided the current step is used.
+ *
+ * @return string
+ *   The next step if found, NULL otherwise.
+ */
+function islandora_ingest_form_get_previous_step(array &$form_state, array $step = NULL) {
+  $step = isset($step) ? $step : islandora_ingest_form_get_step($form_state);
+  $next_step_id = islandora_ingest_form_get_previous_step_id($form_state, $step['id']);
+  if ($next_step_id) {
+    return islandora_ingest_form_get_step($form_state, $next_step_id);
+  }
+  return NULL;
+}
+
 /**
  * Gets the ID of the current step.
  *
@@ -160,12 +206,15 @@ function islandora_ingest_form_get_current_step_id(array &$form_state) {
  *
  * @param array $form_state
  *   The Drupal form state.
+ * @param string $step_id
+ *   The ID of the  step relative to the result, if not provided the current
+ *   step_id is used.
  *
  * @return string
  *   The next step ID if found, NULL otherwise.
  */
-function islandora_ingest_form_get_next_step_id(array &$form_state) {
-  $step_id = islandora_ingest_form_get_current_step_id($form_state);
+function islandora_ingest_form_get_next_step_id(array &$form_state, $step_id = NULL) {
+  $step_id = isset($step_id) ? $step_id : islandora_ingest_form_get_current_step_id($form_state);
   $step_ids = array_keys(islandora_ingest_form_get_steps($form_state));
   $index = array_search($step_id, $step_ids);
   $count = count($step_ids);
@@ -182,12 +231,15 @@ function islandora_ingest_form_get_next_step_id(array &$form_state) {
  *
  * @param array $form_state
  *   The Drupal form state.
+ * @param string $step_id
+ *   The ID of the step relative to the result, if not provided the current
+ *   step_id is used.
  *
  * @return string
  *   The previous step ID if found, NULL otherwise.
  */
-function islandora_ingest_form_get_previous_step_id(array &$form_state) {
-  $step_id = islandora_ingest_form_get_current_step_id($form_state);
+function islandora_ingest_form_get_previous_step_id(array &$form_state, $step_id = NULL) {
+  $step_id = isset($step_id) ? $step_id : islandora_ingest_form_get_current_step_id($form_state);
   $step_ids = array_keys(islandora_ingest_form_get_steps($form_state));
   $index = array_search($step_id, $step_ids);
   if ($index !== FALSE && --$index >= 0) {
@@ -233,13 +285,15 @@ function islandora_ingest_form_decrement_step(array &$form_state) {
  * Build a list of steps given only configuration.
  *
  * XXX: This is used to give an indication of whether there are any steps for a
- *   given list of content models.
+ *   given configuration.
  *
  * @param array $configuration
  *   The list of key/value pairs of configuration.
  */
 function islandora_ingest_get_approximate_steps(array $configuration) {
   try {
+    // @todo, we need to expand the configuration before we can validate it?
+    // I think this need some thinking.
     islandora_ingest_form_validate_configuration($configuration);
   }
   catch (InvalidArgumentException $e) {
@@ -270,16 +324,19 @@ function islandora_ingest_get_approximate_steps(array $configuration) {
  * @return array
  *   The form definition of the current step.
  */
-function islandora_ingest_form_execute_step(array $form, array &$form_state) {
+function islandora_ingest_form_execute_step(array $form, array &$form_state, $step_id = NULL) {
   // Load any required files for the current step.
   islandora_ingest_form_load_include($form_state);
-  $step = islandora_ingest_form_get_step($form_state);
+  $step = isset($step_id) ? islandora_ingest_form_get_step($form_state) : islandora_ingest_form_get_step($form_state, $step_id);
   switch ($step['type']) {
+    case 'callback':
+      // Execute all the consecutive callbacks, and move then attempt to process
+      // the next step.
+      islandora_ingest_form_execute_consecutive_callback_steps($form, $form_state, $step);
+      return islandora_ingest_form_execute_step($form, $form_state);
+
     case 'form':
-      $args = array($form, &$form_state);
-      $args = isset($step['args']) ? array_merge($args, $step['args']) : $args;
-      $form = call_user_func_array($step['form_id'], $args);
-      return islandora_ingest_form_stepify($form, $form_state, $step);
+      return islandora_ingest_form_execute_form_step($form, $form_state, $step);
 
     case 'batch':
       // @todo Implement if possible.
@@ -288,6 +345,56 @@ function islandora_ingest_form_execute_step(array $form, array &$form_state) {
   return array();
 }
 
+/**
+ * Assumes the given $step is a 'form' step.
+ */
+function islandora_ingest_form_execute_form_step(array $form, array &$form_state, array $step) {
+  $args = array($form, &$form_state);
+  $args = isset($step['args']) ? array_merge($args, $step['args']) : $args;
+  $form = call_user_func_array($step['form_id'], $args);
+  return islandora_ingest_form_stepify($form, $form_state, $step);
+}
+
+/**
+ * Assumes the given $step is a 'callback' step.
+ */
+function islandora_ingest_form_execute_consecutive_callback_steps(array $form, array &$form_state, array $step) {
+  do {
+    islandora_ingest_form_execute_callback_step($form, $form_state, $step);
+    islandora_ingest_form_increment_step($form_state);
+    $step = islandora_ingest_form_get_step($form_state);
+  } while (isset($step) && $step['type'] == 'callback');
+}
+
+/**
+ * Assumes the given $step is a 'callback' step.
+ */
+function islandora_ingest_form_execute_callback_step(array $form, array &$form_state, array $step) {
+  $args = array(&$form_state);
+  $args = isset($step['do_function']['args']) ? array_merge($args, $step['do_function']['args']) : $args;
+  call_user_func_array($step['do_function']['function'], $args);
+}
+
+/**
+ * Assumes the given $step is a 'callback' step.
+ */
+function islandora_ingest_form_undo_consecutive_callback_steps(array $form, array &$form_state, array $step) {
+  do {
+    islandora_ingest_form_undo_callback_step($form, $form_state, $step);
+    islandora_ingest_form_decrement_step($form_state);
+    $step = islandora_ingest_form_get_step($form_state);
+  } while (isset($step) && $step['type'] == 'callback');
+}
+
+/**
+ * Assumes the given $step is a 'callback' step.
+ */
+function islandora_ingest_form_undo_callback_step(array $form, array &$form_state, array $step) {
+  $args = array(&$form_state);
+  $args = isset($step['undo_function']['args']) ? array_merge($args, $step['undo_function']['args']) : $args;
+  call_user_func_array($step['undo_function']['function'], $args);
+}
+
 /**
  * Append Prev/Next buttons submit/validation handlers etc.
  *
@@ -297,22 +404,20 @@ function islandora_ingest_form_execute_step(array $form, array &$form_state) {
  *   The Drupal form state.
  *
  * @return array
- *   The stepified drupal form definition for the given step.
+ *   The stepified Drupal form definition for the given step.
  */
 function islandora_ingest_form_stepify(array $form, array &$form_state, $step) {
-  $first_step = islandora_ingest_form_on_first_step($form_state);
-  $last_step = islandora_ingest_form_on_last_step($form_state);
-  $form['prev'] = $first_step ? NULL : islandora_ingest_form_previous_button($form_state);
-  $form['next'] = $last_step ? islandora_ingest_form_ingest_button($form_state) : islandora_ingest_form_next_button($form_state);
-
+  $first_form_step = islandora_ingest_form_on_first_form_step($form_state);
+  $last_form_step = islandora_ingest_form_on_last_form_step($form_state);
+  $form['prev'] = $first_form_step ? NULL : islandora_ingest_form_previous_button($form_state);
+  $form['next'] = $last_form_step ? islandora_ingest_form_ingest_button($form_state) : islandora_ingest_form_next_button($form_state);
   // Allow for a hook_form_FORM_ID_alter().
   drupal_alter(array('form_' . $step['form_id'], 'form'), $form, $form_state, $step['form_id']);
-
   return $form;
 }
 
 /**
- * Checks if we are on the first step.
+ * Checks if we are on the first form step.
  *
  * @param array $form_state
  *   The Drupal form state.
@@ -320,14 +425,16 @@ function islandora_ingest_form_stepify(array $form, array &$form_state, $step) {
  * @return bool
  *   TRUE if we are currently on the first step, FALSE otherwise.
  */
-function islandora_ingest_form_on_first_step(array &$form_state) {
-  $step_id = islandora_ingest_form_get_current_step_id($form_state);
-  $step_ids = array_keys(islandora_ingest_form_get_steps($form_state));
-  return array_search($step_id, $step_ids) == 0;
+function islandora_ingest_form_on_first_form_step(array &$form_state) {
+  $step = NULL;
+  do {
+    $step = islandora_ingest_form_get_previous_step($form_state, $step);
+  } while (isset($step) && $step['type'] != 'form');
+  return !$step;
 }
 
 /**
- * Checks if we are on the last step.
+ * Checks if we are on the last form step.
  *
  * @param array $form_state
  *   The Drupal form state.
@@ -335,11 +442,12 @@ function islandora_ingest_form_on_first_step(array &$form_state) {
  * @return bool
  *   TRUE if we are currently on the last step, FALSE otherwise.
  */
-function islandora_ingest_form_on_last_step(array &$form_state) {
-  $step_id = islandora_ingest_form_get_current_step_id($form_state);
-  $step_ids = array_keys(islandora_ingest_form_get_steps($form_state));
-  $count = count($step_ids);
-  return array_search($step_id, $step_ids) == --$count;
+function islandora_ingest_form_on_last_form_step(array &$form_state) {
+  $step = NULL;
+  do {
+    $step = islandora_ingest_form_get_next_step($form_state, $step);
+  } while (isset($step) && $step['type'] != 'form');
+  return !$step;
 }
 
 /**
@@ -356,11 +464,15 @@ function islandora_ingest_form_on_last_step(array &$form_state) {
 function islandora_ingest_form_previous_button(array &$form_state) {
   // Before we move back to the previous step we should tell the previous step
   // to undo whatever its submit handler did.
-  $prev_step_id = islandora_ingest_form_get_previous_step_id($form_state);
-  $prev_step = islandora_ingest_form_get_step($form_state, $prev_step_id);
-  $form_id = $prev_step['form_id'];
-  $submit_callback = $form_id . '_undo_submit';
-  $submit = function_exists($submit_callback) ? array($submit_callback, 'islandora_ingest_form_previous_submit') : array('islandora_ingest_form_undo_submit');
+  $prev_step = islandora_ingest_form_get_previous_step($form_state);
+  if ($prev_step['type'] == 'form') {
+    $form_id = $prev_step['form_id'];
+    $submit_callback = $form_id . '_undo_submit';
+    $submit = function_exists($submit_callback) ? array($submit_callback, 'islandora_ingest_form_previous_submit') : array('islandora_ingest_form_previous_submit');
+  }
+  else {
+    $submit = array('islandora_ingest_form_previous_submit');
+  }
   return array(
     '#type' => 'submit',
     '#value' => t('Previous'),
@@ -391,6 +503,11 @@ function islandora_ingest_form_previous_button(array &$form_state) {
  */
 function islandora_ingest_form_previous_submit(array $form, array &$form_state) {
   islandora_ingest_form_decrement_step($form_state);
+  $step = islandora_ingest_form_get_step($form_state);
+  // Undo all callbacks that occured after the previous step.
+  if ($step['type'] == 'callback') {
+    islandora_ingest_form_undo_consecutive_callback_steps($form, $form_state, $step);
+  }
   $form_state['rebuild'] = TRUE;
 }
 
@@ -446,8 +563,10 @@ function islandora_ingest_form_next_submit(array $form, array &$form_state) {
  */
 function islandora_ingest_form_stash_info(array &$form_state) {
   $storage = &islandora_ingest_form_get_step_storage($form_state);
-  $storage['values'] = $form_state['values'];
-  unset($form_state['values']);
+  if ($storage) {
+    $storage['values'] = $form_state['values'];
+    unset($form_state['values']);
+  }
 }
 
 /**
@@ -493,12 +612,17 @@ function islandora_ingest_form_ingest_button(array &$form_state) {
  *
  * Attempts to ingest every object built by the previous steps.
  *
- * @param array $form
- *   The Drupal form.
  * @param array $form_state
  *   The Drupal form state.
  */
 function islandora_ingest_form_submit(array $form, array &$form_state) {
+  // Execute any remaining callbacks.
+  islandora_ingest_form_increment_step($form_state);
+  $step = islandora_ingest_form_get_step($form_state);
+  if (isset($step) && $step['type'] == 'callback') {
+    islandora_ingest_form_execute_consecutive_callback_steps($form, $form_state, $step);
+  }
+  // Ingest the objects.
   foreach ($form_state['islandora']['objects'] as $object) {
     try {
       islandora_add_object($object);
@@ -625,6 +749,8 @@ function islandora_ingest_form_get_steps(array &$form_state) {
   $shared_storage = &islandora_ingest_form_get_shared_storage($form_state);
   foreach (islandora_build_hook_list(ISLANDORA_INGEST_STEP_HOOK, $shared_storage['models']) as $hook) {
     // Required for pass by reference.
+    // @todo Change this around so that it isn't passed by reference, there
+    // Is an alter below that can handle that requirement.
     foreach (module_implements($hook) as $module) {
       $function = $module . '_' . $hook;
       $module_steps = (array) $function($form_state);
@@ -635,6 +761,10 @@ function islandora_ingest_form_get_steps(array &$form_state) {
   foreach (islandora_build_hook_list(ISLANDORA_INGEST_STEP_HOOK, $shared_storage['models']) as $hook) {
     drupal_alter($hook, $steps, $form_state);
   }
+  // Add any defaults.
+  foreach ($steps as $key => &$step) {
+    $step['id'] = $key;
+  }
   uasort($steps, 'drupal_sort_weight');
   return $steps;
 }
diff --git a/islandora.api.php b/islandora.api.php
index d1d58f4f..17db59ad 100644
--- a/islandora.api.php
+++ b/islandora.api.php
@@ -304,7 +304,7 @@ function hook_islandora_datastream_modified(FedoraObject $object, FedoraDatastre
 }
 
 /**
- * Notify modules that the given datastream was ingested.
+ * Notify modules that the given datastream was modified.
  *
  * @see hook_islandora_datastream_modified()
  */
@@ -386,15 +386,26 @@ function hook_islandora_undeletable_datastreams(array $models) {
  * @return array
  *   An associative array of associative arrays which define each step in the
  *   ingest process.  Each step should consist of a unique name mapped to an
- *   array of properties (keys) including:
- *   - type: The type of step.  Currently, only "form" is implemented.
- *   - weight: The "weight" of this step--heavier(/"larger") values sink to the
- *     end of the process while smaller(/"lighter") values are executed first.
+ *   array of properties (keys) which take different paramaters based upon type:
+ *   - type: Type of step.  Only "form" and "callback" are implemented so far.
+ *   Required "form" type specific parameters:
  *   - form_id: The form building function to call to get the form structure
  *     for this step.
  *   - args: An array of arguments to pass to the form building function.
- *   And may optionally include both:
+ *   Required "callback" type specific parameters:
+ *   - do_function: An associate array including:
+ *       - 'function': The callback function to be called.
+ *       - 'args': An array of arguments to pass to the callback function.
+ *   - undo_function: An associate array including:
+ *       - 'function': The callback function to be called to reverse the
+ *          executed action in the ingest steps.
+ *       - 'args': An array of arguments to pass to the callback function.
+ *   Shared parameters between both types:
+ *   - weight: The "weight" of this step--heavier(/"larger") values sink to the
+ *     end of the process while smaller(/"lighter") values are executed first.
+ *   Both types may optionally include:
  *   - module: A module from which we want to load an include.
+ *   "Form" type may optionally include:
  *   - file: A file to include (relative to the module's path, including the
  *     file's extension).
  */
@@ -406,6 +417,18 @@ function hook_islandora_ingest_steps(array $form_state) {
       'form_id' => 'my_cool_form',
       'args' => array('arg_one', 'numero deux'),
     ),
+    'my_cool_step_callback' => array(
+      'type' => 'callback',
+      'weight' => 2,
+      'do_function' => array(
+        'function' => 'my_cool_execute_function',
+        'args' => array('arg_one', 'numero deux'),
+      ),
+      'undo_function' => array(
+        'function' => 'my_cool_undo_function',
+        'args' => array('arg_one', 'numero deux'),
+      ),
+    ),
   );
 }
 /**