diff --git a/src/CPnts/CPnts_AbscissaPoint.cdl b/src/CPnts/CPnts_AbscissaPoint.cdl
index 8886bc5c35..466cd49e20 100644
--- a/src/CPnts/CPnts_AbscissaPoint.cdl
+++ b/src/CPnts/CPnts_AbscissaPoint.cdl
@@ -153,11 +153,16 @@ is
   Perform(me: in out; Abscissa, U0, Resolution : Real)
     ---Purpose: Computes the point at the distance <Abscissa> of
     --          the curve.
+    --          U0 is the parameter of the point from which the distance
+    --          is measured.
     is static;
  
   Perform(me: in out; Abscissa, U0, Ui, Resolution : Real)
     ---Purpose: Computes the point at the distance <Abscissa> of
     --          the curve.
+    --          U0 is the parameter of the point from which the distance
+    --          is measured and Ui is the starting value for the iterative
+    --          process (should be close to the final solution).
     is static;
     
   AdvPerform(me: in out; Abscissa, U0, Ui, Resolution : Real)
@@ -166,6 +171,9 @@ is
     --          to use this method in right way it is necessary to call  
     --          empty consructor. then call method Init with  
     --	        Tolerance = Resolution, then call AdvPermorm.     
+    --	        U0 is the parameter of the point from which the distance
+    --	        is measured and Ui is the starting value for the iterative
+    --	        process (should be close to the final solution).
     is static;  
        
   IsDone(me)