diff --git a/masque/file/gdsii.py b/masque/file/gdsii.py
index 3766872..31a287f 100644
--- a/masque/file/gdsii.py
+++ b/masque/file/gdsii.py
@@ -23,6 +23,8 @@ from ..shapes import Polygon, Path
 from ..utils import rotation_matrix_2d, get_bit, set_bit, vector2, is_scalar
 from ..utils import remove_colinear_vertices, normalize_mirror
 
+#TODO document how GDS rotation / mirror works
+#TODO absolute positioning
 
 __author__ = 'Jan Petykiewicz'