Docs: Add note on unsupported Django admin

docs/source/internals/sandbox.rst

@@ -36,8 +36,8 @@ The sandbox is, in effect, the blank canvas upon which you can build your site.
 The demo site
 -------------
 
-The demo site is *the* reference Oscar project as it illustates how Oscar can be
-redesigned and customised to build a e-commerce store.  The demo site is a
+The demo site is *the* reference Oscar project as it illustrates how Oscar can
+be redesigned and customised to build an e-commerce store. The demo site is a
 sailing store selling a range of different product types.
 
 The customisations on top of core Oscar include:
@@ -50,6 +50,18 @@ The customisations on top of core Oscar include:
 .. _django-oscar-paypal: https://github.com/tangentlabs/django-oscar-paypal
 .. _django-oscar-datacash: https://github.com/tangentlabs/django-oscar-datacash
 
+.. note::
+
+    Both the sandbox and demo site have the Django admin interface wired up.
+    This is done as a convenience for developers to browse the database at
+    ORM level. It also serves as an easy method to manually create a product
+    class or partner.
+
+    Having said that, the Django admin interface is *unsupported* and will fail
+    or be of little use for some models. At the time of writing, editing
+    products in the admin is clunky and slow, and editing categories is
+    not supported at all.
+
 Browse the external sandbox site
 ================================