diff --git a/org_rw/dom.py b/org_rw/dom.py
index dd9c7d7..bc24272 100644
--- a/org_rw/dom.py
+++ b/org_rw/dom.py
@@ -1,32 +1,23 @@
-class PropertyDrawerNode:
+class DrawerNode:
     def __init__(self):
         self.children = []
 
     def append(self, child):
         self.children.append(child)
 
+
+class PropertyDrawerNode(DrawerNode):
+
     def __repr__(self):
         return "<Properties: {}>".format(len(self.children))
 
 
-class LogbookDrawerNode:
-    def __init__(self):
-        self.children = []
-
-    def append(self, child):
-        self.children.append(child)
-
+class LogbookDrawerNode(DrawerNode):
     def __repr__(self):
         return "<LogBook: {}>".format(len(self.children))
 
 
-class ResultsDrawerNode:
-    def __init__(self):
-        self.children = []
-
-    def append(self, child):
-        self.children.append(child)
-
+class ResultsDrawerNode(DrawerNode):
     def __repr__(self):
         return "<Results: {}>".format(len(self.children))
 
@@ -82,12 +73,16 @@ class ListItem:
 
 
 class BlockNode:
+    def __init__(self):
+        self.children = []
+
     def append(self, child):
-        raise NotImplementedError()
+        self.children.append(child)
 
 
 class CodeBlock(BlockNode):
     def __init__(self, header, subtype):
+        super().__init__()
         self.header = header
         self.lines = None
         self.subtype = subtype
diff --git a/org_rw/org_rw.py b/org_rw/org_rw.py
index c3d9f57..6cbd04b 100644
--- a/org_rw/org_rw.py
+++ b/org_rw/org_rw.py
@@ -378,7 +378,7 @@ class Headline:
             elif isinstance(line, Text):
                 if isinstance(current_node, dom.BlockNode):
                     current_node.append(dom.Text(line))
-                elif isinstance(current_node, dom.LogbookDrawerNode):
+                elif isinstance(current_node, dom.DrawerNode):
                     current_node.append(dom.Text(line))
                 else:
                     if isinstance(current_node, dom.TableNode):
@@ -390,13 +390,18 @@ class Headline:
                     tree.append(dom.Text(text_to_dom(line.contents, line)))
 
             elif isinstance(line, ListItem):
-                if current_node is None or isinstance(current_node, dom.TableNode):
+                if (current_node is None
+                    or isinstance(current_node, dom.TableNode)
+                    or isinstance(current_node, dom.BlockNode)
+                    or isinstance(current_node, dom.DrawerNode)
+                ):
                     current_node = dom.ListGroupNode()
-                    tree.append(current_node)
-                    indentation_tree = [current_node]
+                    if current_node is None:
+                        tree.append(current_node)
+                    indentation_tree.append(current_node)
                 if not isinstance(current_node, dom.ListGroupNode):
                     if not isinstance(current_node, dom.ListGroupNode):
-                        logging.warning("Expected a {}, found: {} on line {} on {}".format(dom.ListGroupNode, current_node, line.linenum, self.doc.path))
+                        raise Exception("Expected a {}, found: {} on line {} on {}".format(dom.ListGroupNode, current_node, line.linenum, self.doc.path))
                         # This can happen. Frequently inside a LogDrawer
 
                 if len(indentation_tree) > 0 and (
@@ -441,6 +446,7 @@ class Headline:
                 if current_node is None:
                     current_node = dom.TableNode()
                     tree.append(current_node)
+                    # TODO: Allow indentation of this element inside others
                     indentation_tree = [current_node]
                 if not isinstance(current_node, dom.TableNode):
                     if not isinstance(current_node, dom.TableNode):
@@ -482,36 +488,39 @@ class Headline:
                     assert current_node is None
                     current_node = dom.PropertyDrawerNode()
                     tree.append(current_node)
+                    # TODO: Check if this can be nested
+                    indentation_tree = [current_node]
                 elif content.strip().upper() == ":LOGBOOK:":
                     assert current_node is None
                     current_node = dom.LogbookDrawerNode()
                     tree.append(current_node)
+                    # TODO: Check if this can be nested
+                    indentation_tree = [current_node]
                 elif content.strip().upper() == ":END:":
-                    if current_node is None:
-                        logging.warning('Finished node (:END:) with no known starter')
+                    if current_node is None and len(indentation_tree) == 0:
+                        logging.error('Finished node (:END:) with no known starter')
                     else:
-                        tree_up = list(tree)
+                        tree_up = list(indentation_tree)
                         while len(tree_up) > 0:
                             node = tree_up[-1]
-                            if (isinstance(
-                                    node, dom.PropertyDrawerNode
-                            ) or isinstance(
-                                node, dom.LogbookDrawerNode
-                            ) or isinstance(
-                                node, dom.ResultsDrawerNode
-                            )):
-                                tree = tree_up
+                            if isinstance(node, dom.DrawerNode):
+                                indentation_tree = tree_up
                                 current_node = node
+                                tree_up.pop(-1)
                                 break
                             else:
                                 tree_up.pop(-1)
                         else:
                             raise Exception('Unexpected node ({}) on headline (id={}), line {}'.format(current_node, self.id, linenum))
+                        if self.id == 'd07fcf27-d6fc-41e3-a9d0-b2e2902aec23':
+                            print("Found node:", current_node)
                         current_node = None
-                    tree.pop()
                 elif content.strip().upper() == ":RESULTS:":
                     assert current_node is None
                     current_node = dom.ResultsDrawerNode()
+
+                    # TODO: Allow indentation of these blocks inside others
+                    indentation_tree = [current_node]
                     tree.append(current_node)
                 else:
                     raise Exception("Unknown structural line: {}".format(line))