diff --git a/core/TESTS/test_urls.py b/core/TESTS/test_urls.py
index df34ee6..7af8efc 100644
--- a/core/TESTS/test_urls.py
+++ b/core/TESTS/test_urls.py
@@ -6,6 +6,16 @@ so any path that relies on data being in the database will fail.
 
 https://docs.djangoproject.com/en/dev/topics/testing/tools/
 
+We are not using 
+https://github.com/FactoryBoy/factory_boy
+because we are trying to minimise the number of 3rd-party packages because they expose us to update hell,
+as experience in 2019-2020.
+However we could use 
+https://docs.python.org/dev/library/unittest.mock.html
+as this is now part if python - if we can get our heads around it.
+
+The tests in this file:
+
 The code  {% url THING %}  or {% url THING PARAMETER %} appears a hundred times or more in the troggle/templates/ HTML template files.
 This is the template synstax for 
 reverse('THING')
@@ -18,6 +28,8 @@ parameters should be fine as this is fundamental Django stuff which will have be
 But the reverse() function is purely syntactical, the PARAMETER is just a string which is applied to
 the url. So this is not testing anything important really. See the test_url_threed() below.
 
+These url lines all come from templates/*.html
+
 1. No tests: No parameters
 
 {% url "caveindex" %}