diff --git a/src/ptf/ptf_torus.scad b/src/ptf/ptf_torus.scad
index d65ecafa..16013dfd 100644
--- a/src/ptf/ptf_torus.scad
+++ b/src/ptf/ptf_torus.scad
@@ -1,12 +1,15 @@
+/**
+* ptf_torus.scad
+*
+* @copyright Justin Lin, 2020
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib2x-ptf_torus.html
+*
+**/ 
+
 use <ptf/ptf_rotate.scad>;
 
-/*
-    size: The size of a rectangle.
-    point: A point in the rectangle.
-    radius: torus [R, r]
-    angle: torus [A, a].
-    twist: The number of degrees of through which the rectangle is twisted.
-*/
 function ptf_torus(size, point, radius, angle = [360, 360], twist = 0) =
     let(
         xlen = size[0],