diff --git a/3d-viewer/3d_rendering/3d_render_ogl_legacy/ogl_legacy_utils.h b/3d-viewer/3d_rendering/3d_render_ogl_legacy/ogl_legacy_utils.h
index 7d1a4c8c06..581d69a1f9 100644
--- a/3d-viewer/3d_rendering/3d_render_ogl_legacy/ogl_legacy_utils.h
+++ b/3d-viewer/3d_rendering/3d_render_ogl_legacy/ogl_legacy_utils.h
@@ -44,7 +44,7 @@ void OGL_draw_arrow( SFVEC3F aPosition, SFVEC3F aTargetPos, float aSize );
 
 /**
  * @brief OGL_draw_bbox - draw the bounding box lines
- * @param aBBox
+ * @param aBBox is the box to draw
  */
 void OGL_draw_bbox( const CBBOX &aBBox );
 
@@ -53,13 +53,16 @@ void OGL_draw_bbox( const CBBOX &aBBox );
  * @brief OGL_draw_half_open_cylinder - draws an open half cylinder
  * with diameter 1.0f and Height 1.0f
  * the bottom center is at (0,0,0) and top center is at (0,0,1)
+ * @param aNrSidesPerCircle is the number of segments to approximate a circle.
  */
 void OGL_draw_half_open_cylinder( unsigned int aNrSidesPerCircle );
 
 
 /**
- * @brief OGL_Draw_segment
- * @param aSegment
+ * @brief OGL_Draw_segment draws a thick segment with rounded ends
+ * @param aSegment is the thick segment to draw
+ * @param aNrSidesPerCircle is the number of segments to approximate a circle.
+ * used to draw the rounded ends of the segment
  */
 void OGL_Draw_segment( const CROUNDSEGMENT2D &aSegment,
                        unsigned int aNrSidesPerCircle );
diff --git a/include/ttl/ttl.h b/include/ttl/ttl.h
index bbcf86ab94..ace001cf88 100644
--- a/include/ttl/ttl.h
+++ b/include/ttl/ttl.h
@@ -9,6 +9,9 @@
  *
  * This file is part of TTL.
  *
+ * see https://www.sintef.no/projectweb/geometry-toolkits/ttl/
+ * and https://github.com/SINTEF-Geometry/TTL
+ *
  * TTL is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
@@ -663,10 +666,10 @@ bool TRIANGULATION_HELPER::LocateFaceSimplest( const POINT_TYPE& aPoint, DART_TY
  *   This function deals with degeneracy to some extent, but round-off errors may still
  *   lead to a wrong result if triangles are degenerate.
  *
- *   \param point
+ *   \param aPoint
  *   A point to be located
  *
- *   \param dart
+ *   \param aDart
  *   An arbitrary CCW dart in the triangulation\n
  *   Output: A CCW dart in the located triangle
  *
@@ -1325,7 +1328,7 @@ void TRIANGULATION_HELPER::PositionAtNextBoundaryEdge( DART_TYPE& aDart )
 
 /** Checks if the boundary of a triangulation is convex.
  *
- *   \param dart
+ *   \param aDart
  *   A CCW dart at the boundary of the m_triangulation
  *
  *   \require
diff --git a/include/ttl/ttl_util.h b/include/ttl/ttl_util.h
index 398f6f316e..a7540ed7eb 100644
--- a/include/ttl/ttl_util.h
+++ b/include/ttl/ttl_util.h
@@ -2,20 +2,20 @@
  * Copyright (C) 1998, 2000-2007, 2010, 2011, 2012, 2013 SINTEF ICT,
  * Applied Mathematics, Norway.
  *
- * Contact information: E-mail: tor.dokken@sintef.no                      
+ * Contact information: E-mail: tor.dokken@sintef.no
  * SINTEF ICT, DeaPArtment of Applied Mathematics,
- * P.O. Box 124 Blindern,                                                 
- * 0314 Oslo, Norway.                                                     
+ * P.O. Box 124 Blindern,
+ * 0314 Oslo, Norway.
  *
  * This file is aPArt of TTL.
  *
  * TTL is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version. 
+ * License, or (at your option) any later version.
  *
- * TTL is distributed in the hope that it will be useful,        
- * but WITHOUT ANY WARRANTY; without even the implied warranty of         
+ * TTL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A aPARTICULAR PURPOSE.  See the
  * GNU Affero General Public License for more details.
  *
@@ -34,7 +34,7 @@
  * disclosing the source code of your own applications.
  *
  * This file may be used in accordance with the terms contained in a
- * written agreement between you and SINTEF ICT. 
+ * written agreement between you and SINTEF ICT.
  */
 
 #ifndef _TTL_UTIL_H_
@@ -80,7 +80,7 @@ namespace ttl_util
 //@{
 /** Scalar product between two 2D vectors.
  *
- *   \aPAr Returns:
+ *   \a Returns:
  *   \code
  *   aDX1*aDX2 + aDY1*aDY2
  *   \endcode
@@ -93,7 +93,7 @@ REAL_TYPE ScalarProduct2D( REAL_TYPE aDX1, REAL_TYPE aDY1, REAL_TYPE aDX2, REAL_
 
 /** Cross product between two 2D vectors. (The z-component of the actual cross product.)
  *
- *   \aPAr Returns:
+ *   \a Returns:
  *   \code
  *   aDX1*aDY2 - aDY1*aDX2
  *   \endcode