1 files changed, 2 insertions, 0 deletions
diff --git a/TODO.txt b/TODO.txt
index aa24763..83d4e7c 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -67,6 +67,8 @@ o Primitives
 o 2D Subsystem
   - Add generic 3D->2D projection statements
   - 2D->3D using clipping plane
+o Built-in modules
+  - extrude*: Allow the base 2D primitive to have a Z value
 o Advanced Transformations
   - Add statement for 2D and 3D minkowski sum
   - Add statement for refinement via surface subdivision