diff --git a/doc/source/users/tutorials/1dc/data_organisation.rst b/doc/source/users/tutorials/1dc/data_organisation.rst
index 8463b9f..d06642d 100644
--- a/doc/source/users/tutorials/1dc/data_organisation.rst
+++ b/doc/source/users/tutorials/1dc/data_organisation.rst
@@ -176,6 +176,10 @@ An example of an ``EVENTS`` table is shown below.
 
    *Content of an event list*
 
+.. warning::
+   The time stamps in the ``TIME`` column are **not** necessarily in ascending
+   order.
+
 
 Observation Definition Files
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^