diff --git a/TODO b/TODO
index 68a8088b26833380e5a5614ff5b79274e2329c2e..f940801f00f9c15e24f8290e178b392f825363ba 100644
--- a/TODO
+++ b/TODO
@@ -66,6 +66,8 @@ and maintain.
 ## Naming of classes and members
 
 * ignoreNodes_ should be called ignore_/ignoreIndices_/ignoreComponents_
+* In some classes the type of the matrix is called 'OperatorType'.
+  This is old 'dune-fem speak', and should be replaced by 'MatrixType'.