diff --git a/.ipynb_checkpoints/not_so_obvious_python_stuff-checkpoint.ipynb b/.ipynb_checkpoints/not_so_obvious_python_stuff-checkpoint.ipynb
index 514778f..48d834c 100644
--- a/.ipynb_checkpoints/not_so_obvious_python_stuff-checkpoint.ipynb
+++ b/.ipynb_checkpoints/not_so_obvious_python_stuff-checkpoint.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:6bc56360203df31596f6332e4b5c73effb2572d18b60bdf6a792042e2fde8c12"
+  "signature": "sha256:0c860c383edcd7622b0c660eb989513e90496c7350916bae1ddb6c10f29fab2c"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -40,9 +40,10 @@
       "- [The C3 class resolution algorithm for multiple class inheritance](#c3_class_res)\n",
       "- [The behavior of += for lists](#pm_in_lists)\n",
       "- [`True` and `False` in the datetime module](#datetime_module)\n",
-      "- [Python reuses objects for small integers](#python_small_int)\n",
+      "- [Python reuses objects for small integers - always use \"==\" for equality, \"is\" for identity](#python_small_int)\n",
       "- [Shallow vs. deep copies if list contains other structures and objects](#shallow_vs_deep)\n",
-      "- [Picking True values from and and or expressions](#false_true_expressions)"
+      "- [Picking True values from and and or expressions](#false_true_expressions)\n",
+      "- [Don't use mutable objects as default arguments for functions!](#def_mutable_func)"
      ]
     },
     {
@@ -189,10 +190,12 @@
       "<br>\n",
       "<br>\n",
       "<a name='python_small_int'></a>\n",
-      "## Python reuses objects for small integers \n",
+      "## Python reuses objects for small integers - always use \"==\" for equality, \"is\" for identity\n",
       "\n",
       "This oddity occurs, because Python tends to stores small integers as the same object, but not so for larger ones!  \n",
-      "(*I received a comment that this is in fact a CPython artefact and must not necessarily be true in all implementations of Python!*)"
+      "(*I received a comment that this is in fact a CPython artefact and must not necessarily be true in all implementations of Python!*)\n",
+      "\n",
+      "So the take home message is: always use \"==\" for equality, \"is\" for identity!"
      ]
     },
     {
@@ -335,7 +338,7 @@
      "source": [
       "<br>\n",
       "<br>\n",
-      "<a name='def_mutable_func></a>\n",
+      "<a name='def_mutable_func'></a>\n",
       "## Don't use mutable objects as default arguments for functions!"
      ]
     },
diff --git a/not_so_obvious_python_stuff.ipynb b/not_so_obvious_python_stuff.ipynb
index 7dc2ad4..48d834c 100644
--- a/not_so_obvious_python_stuff.ipynb
+++ b/not_so_obvious_python_stuff.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:158ad35cd56abe8905983dc63421b3b7b54d28a947df54f67a3b7f0a53e31481"
+  "signature": "sha256:0c860c383edcd7622b0c660eb989513e90496c7350916bae1ddb6c10f29fab2c"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -40,7 +40,7 @@
       "- [The C3 class resolution algorithm for multiple class inheritance](#c3_class_res)\n",
       "- [The behavior of += for lists](#pm_in_lists)\n",
       "- [`True` and `False` in the datetime module](#datetime_module)\n",
-      "- [Python reuses objects for small integers](#python_small_int)\n",
+      "- [Python reuses objects for small integers - always use \"==\" for equality, \"is\" for identity](#python_small_int)\n",
       "- [Shallow vs. deep copies if list contains other structures and objects](#shallow_vs_deep)\n",
       "- [Picking True values from and and or expressions](#false_true_expressions)\n",
       "- [Don't use mutable objects as default arguments for functions!](#def_mutable_func)"
@@ -190,10 +190,12 @@
       "<br>\n",
       "<br>\n",
       "<a name='python_small_int'></a>\n",
-      "## Python reuses objects for small integers \n",
+      "## Python reuses objects for small integers - always use \"==\" for equality, \"is\" for identity\n",
       "\n",
       "This oddity occurs, because Python tends to stores small integers as the same object, but not so for larger ones!  \n",
-      "(*I received a comment that this is in fact a CPython artefact and must not necessarily be true in all implementations of Python!*)"
+      "(*I received a comment that this is in fact a CPython artefact and must not necessarily be true in all implementations of Python!*)\n",
+      "\n",
+      "So the take home message is: always use \"==\" for equality, \"is\" for identity!"
      ]
     },
     {