diff --git a/NOTES.md b/NOTES.md
index a7435d1e4..8db04d9dd 100644
--- a/NOTES.md
+++ b/NOTES.md
@@ -3,14 +3,44 @@
 iD implements a [persistent data structure](http://en.wikipedia.org/wiki/Persistent_data_structure)
 over the OSM data model.
 
-To be clear, this data model is something like
-
+The data model of OSM is something like
 
     root -> relations (-> relations) -> ways -> nodes
        \                             \> nodes
         \-  ways -> nodes
          \- nodes
 
+In English:
+
+* Relations have (ways, nodes, relations)
+* Ways have (nodes)
+* Nodes have ()
+
+## Persistence
+
+The idea is that we keep every _changed_ of an object around, but reuse
+unchanged objects between versions.
+
+So, possibly the datastructure on first load is like
+
+```javascript
+{
+    1: [1],
+    2: [2],
+    3: [3]
+}
+```
+
+After one edit in which the object formerly known as `1` acquires a new
+version, it is like:
+
+```javascript
+{
+    1: [4, 1],
+    2: [2, 2],
+    3: [3, 3]
+}
+```
 
 ## Performance
 
diff --git a/docs/events.txt b/docs/events.txt
deleted file mode 100755
index 0a3a7e1ac..000000000
--- a/docs/events.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-== Entities ==
-
-Listeners are created in NodeUI and WayUI for each item's hitzone.
-
-MouseEvents proceed like this:
-
-* Event triggered on EntityUI, calling EntityUI.entityMouseEvent(event)
-* This calls Controller.entityMouseEvent(event,entityUI)
-* This updates the state from ControllerState.processMouseEvent(event,entityUI)
-
-== Non-entities ==
-
-* onmousemove in Map.js calls processMove, which calls Controller.entityMouseEvent(event,null)
-* onclick in Map.js calls clickSurface, which calls Controller.entityMouseEvent(event,null)
diff --git a/docs/todo.txt b/docs/todo.txt
deleted file mode 100755
index 2f8dcd48e..000000000
--- a/docs/todo.txt
+++ /dev/null
@@ -1,62 +0,0 @@
-DrawWay to do:
-* start from a POI node ("convert into way?")
-* still allow dragging the map
-
-Drag and drop to do:
-* presentation
-* cope with dragging onto anything, not just blank areas of the map
-
-Next to do:
-* drag nodes
-* remove trailing commas (for IE!)
-
-Renderer to do
-* hover!
-* NodeUI renderer needs a default width/height so that clicking a POI without them still shows the highlight
-* Fix 'special values' in RuleSet - they're not really special for SVG etc.
-* Labels other than text-on-path
-* Node headings (for locks etc.)
-* Dragging needs tolerance (i.e. less than n pixels and n seconds)
-
-Tagging to do
-* dijitTooltipConnector is wrong when an entityUI is clicked
-
-ControllerStates to do:
-* Try to share as much code as possible
-* Draw way controller states:
-	- NoSelection (next click starts, or selects)
-	- SelectedWay (next click starts, or selects)
-	- SelectedPOINode (next click starts, or selects)
-	- DrawWay (next click continues, or completes and edits)
-
-Events
-* EntityMouseEvent seems to get called twice most of the time when moving the mouse around in DrawWay
-* Maybe we should just broadcast to the Controller, and the Controller knows what to do. In other words:
-	- undo says "the following entities have changed: way 5, node 3, way 7, relation 8"
-	- the Controller gets the message and invokes a redraw
-	- no need for anything else to listen
-
-------------------------------------------------
-
-Modes:
-1. Add point
-2. Add street or shape
-3. Edit object
-	3a. edit tags (and relation memberships, etc.)
-	3b. move object
-	3c. delete object
-	3d. extend way
-	3e. geometry operations (like P2 Toolbox)
-
-In 'edit': double-clicking goes into "draw shape"; double-clicking then Enter creates POI
-
-Needs greyed-out "step-by-step" window for draw modes:
-	Click at the start point to begin drawing
-	Add each point, click by click
-	Double-click when you've finished
-	Then choose what it is
-
-With buttons at the bottom:
-	Finish
-	Cancel
-	Undo last