diff --git a/source/dcmnttn/documenting.rst b/source/dcmnttn/documenting.rst
new file mode 100644
index 0000000..eab735f
--- /dev/null
+++ b/source/dcmnttn/documenting.rst
@@ -0,0 +1,6 @@
+Documenting
+
+.. py:function:: enumerate(sequence[, start=0])
+
+   Return an iterator that yields tuples of an index and an item of the
+   *sequence*. (And so on.)