diff --git a/docs/object-attribute-system.md b/docs/object-attribute-system.md
deleted file mode 100644
index 952c5c99..00000000
--- a/docs/object-attribute-system.md
+++ /dev/null
@@ -1,165 +0,0 @@
-# Object Attributes System
-
-> This document cover two notions, the edition of attributes and the impact it has relatively to the others Objects.
-
-## Edition of Attributes
-
-> There is no limit to how many attributes can be defined to an Object.
-
-In the "Object Attributes" section of the "Object Edit" Page, the first row is a form to create and append a new attribute. It requires two elements, the name of the attribute and its type (`String`, `Number`, `Boolean`, `Array`, `Object`, `Function`, `Null`). Click 'Add' to create the attribute.
-
-> Within a same Object, each attribute's name must be unique.
-
-Once created, the new attributes appears right below and the ability to associate a value to it is now available. Depending on the type of the attribute, the interface will vary.
-
-- String value input is type String.
-- Number value input is type Number.
-- Booleans value input appears as a switch, true by default.
-- Arrays and Objects content are hidable / showable via the "Show/Hide content" button on the right of the attribute. There is no limit on the depth of Object/Array, however, after a certain level, the interface will start to feel narrow.
-- String value input is type String.
-- Null will not display any input.
-- Function will offer to select from all available functions, save on select.
-
-Any attribute can be delete by clicking on the 'trash' icon on the right hand of it.
-
-Here an example of how the section looks like.
-![object-attributes](img/object-attributes.png)
-
-## Attributes and RelationShips
-
-When an attributes is set to an Object, other Objects, associated to this particular Object, will have access to it. Which means that, if an Object A is added as a child of an Object B, A will embed its attributes within the instance of B.
-
-Object's attributes follow a hierarchy when associated to an other Object.
-The **defaults attributes** of a child, the ones defined in the original Object are the weakest ones. A **children attribute** is applied to all the children and override the default attributes. Finally, **relation attribute** is the strongest one, it override Default Attributes and Children Attributes.
-
-When an object and its relationship are resolved, the three structures (`attrs`, `childrenAttrs`, `childAttrs`) are merged.
-
-The following json shows how the object would be represented:
-
-```json
-{
-  "children": {
-    "printalphabet": {
-      "duration": 3600,
-      "xp": 800,
-      "isBonus": true
-    }
-  }
-}
-```
-
-Children
-![children](img/children.png)
-
-Child
-![child-capture](img/child-capture.png)
-
-## Detailed example
-
-Let's create a few `exercises` objects
-
-> swap
-
-```js
-{
-  "id": 12344,
-  "title": "swap",
-  "attrs": {
-    "language": "go",
-    "duration": 7200
-  }
-}
-```
-
-> printalphabet
-
-```js
-{
-  "id": 12345,
-  "title": "printalphabet-v2",
-  "attrs": {
-    "language": "go",
-    "duration": 3600
-  }
-}
-```
-
-We can now create a parent object that will reference them and link them.
-
-This allow you to specify the structuration of your pedagogical content.
-
-I'll make a quest that regroup those 2 exercises:
-
-> quest-03
-
-```js
-{
-  "id": 12346,
-  "title": "quest-03",
-  "attrs": {},
-  "childrenAttrs": {
-    "xp": 800,
-    "duration": 4800,
-  },
-  "children": {
-    "printalphabet": {
-      "ref": 12345,
-      "index": 0,
-      "attrs": {
-        "duration": 7200
-      }
-    },
-    "swap": {
-      "ref": 12344,
-      "index": 1,
-      "attrs": {}
-    }
-  }
-}
-```
-
-All done, now when rendering an object, attributes are merged like so:
-
-> rendered quest object
-
-```js
-{
-  "id": 12346,
-  "title": "quest-03",
-  "attrs": {},
-  "children": {
-    "printalphabet": {
-      "ref": 12345,
-      "index": 0,
-      "attrs": {
-        "language": "go",
-        "xp": 800,
-        "duration": 7200
-      }
-    },
-    "swap": {
-      "ref": 12344,
-      "index": 1,
-      "attrs": {
-        "language": "go",
-        "xp": 800,
-        "duration": 4800
-      }
-    }
-  }
-}
-```
-
-First we apply the **default attributes** from the referenced object.
-
-> Here `duration` and `language` are applied.
-
-Then we apply the **children attributes** to every child.
-
-> In this case we override every `duration` to 4800 and add the new `xp` attribute.
-
-After that we apply the **relation attributes**, that are the most specific and as such,
-override all others attributes.
-
-> In this case only the `printalphabet` relation had attributes and so we apply
-> the given `duration` to the final merged object.