diff --git a/matlab/bksup1.m b/matlab/bksup1.m
index 848d6507d..a7516916c 100644
--- a/matlab/bksup1.m
+++ b/matlab/bksup1.m
@@ -1,7 +1,22 @@
-% Copyright (C) 2001 Michel Juillard
-%
 function d = bksup1(ny,jcf)
 
+% function d = bksup1(ny,jcf)
+% Solves deterministic models recursively by backsubstitution for one lead/lag
+%
+% INPUTS
+%    ny:             number of endogenous variables
+%    jcf:            variables index forward
+%    
+% OUTPUTS
+%    d:              vector of backsubstitution results
+%
+% SPECIAL REQUIREMENTS
+%    none
+%  
+% part of DYNARE, copyright Dynare Team (2003-2007)
+% Gnu Public License.
+
+
 global options_ iyf c 
 
 ir = [(options_.periods-2)*ny+1:ny+(options_.periods-2)*ny] ;
@@ -17,3 +32,4 @@ end
 d = c(:,jcf) ;
 
 return ;
+