diff --git a/doc/texinfo/opt_plugin.texi b/doc/texinfo/opt_plugin.texi
index 4d9650d4c9bcd16f53d3fe87bfbeefcd2fad6703..9e5c1ec3dd347c37c783a4e19863e51d78c3314e 100644
--- a/doc/texinfo/opt_plugin.texi
+++ b/doc/texinfo/opt_plugin.texi
@@ -402,11 +402,12 @@ Default value: @code{-1}
 @end table
 
 @item Plugin(Transform)
-Plugin(Transform) transforms the node coordinates
-of the elements in the view `iView' by the matrix
-[`A11' `A12' `A13']
-[`A21' `A22' `A23']
-[`A31' `A32' `A33'].
+Plugin(Transform) transforms the homogenous
+node coordinates (x,y,z,1) of the elements in
+the view `iView' by the matrix
+[`A11' `A12' `A13' `T1']
+[`A21' `A22' `A23' `T2']
+[`A31' `A32' `A33' `T3'].
 If `swapOrientation' is set, the orientation of the
 elements is reversed. If `iView' < 0, the plugin
 is run on the current view.
@@ -433,6 +434,12 @@ Default value: @code{0}
 Default value: @code{0}
 @item A33
 Default value: @code{1}
+@item T1
+Default value: @code{0}
+@item T2
+Default value: @code{0}
+@item T3
+Default value: @code{0}
 @item swapOrientation
 Default value: @code{0}
 @item iView