diff --git a/NOTES.md b/NOTES.md
new file mode 100644
index 0000000..67d7be2
--- /dev/null
+++ b/NOTES.md
@@ -0,0 +1,3 @@
+Documentation for graph-easy, which is used to convert diag_inp.txt to
+the outputs, diag.*:
+http://bloodgate.com/perl/graph/manual/index.html