diff --git a/src/common/libmmgtypes.h b/src/common/libmmgtypes.h
index a8da4d7c6..2c373593d 100644
--- a/src/common/libmmgtypes.h
+++ b/src/common/libmmgtypes.h
@@ -386,7 +386,7 @@ typedef MMG5_Quad * MMG5_pQuad;
  *
  * \brief Structure to store tetrahedra of an MMG mesh.
  *
- * \remark Numbering convention
+ * \remark The numbering conventions are illustrated below. Face i lies opposite to vertex i.
  * \verbatim
  *      Vertices                     Edges                       Faces           *
  *           3                          .                           .            *
@@ -410,8 +410,9 @@ typedef struct {
   MMG5_int ref; /*!< Reference of the tetrahedron */
   MMG5_int base;
   MMG5_int mark; /*!< Used for delaunay */
-  MMG5_int xt; /*!< Index of the surface \ref MMG5_xTetra associated to
-                 the tetrahedron*/
+  MMG5_int xt; /*!< Index of the surface \ref MMG5_xTetra associated to the
+                 tetrahedron (only for tetrahedra that are adjacent to
+                 surfaces) */
   MMG5_int flag;
   int16_t  tag;
 } MMG5_Tetra;
diff --git a/src/mmg3d/libmmg3d.h b/src/mmg3d/libmmg3d.h
index 477f37ca9..d80c3d282 100644
--- a/src/mmg3d/libmmg3d.h
+++ b/src/mmg3d/libmmg3d.h
@@ -355,8 +355,9 @@ LIBMMG3D_EXPORT int  MMG3D_Set_inputParamName(MMG5_pMesh mesh, const char* fpara
  * \brief Initialize a solution field.
  * \param mesh pointer to the mesh structure.
  * \param sol pointer to the sol structure.
- * \param typEntity type of entities on which the solution is defined (vertices, triangles, ...,
- *        see \ref MMG5_entities for possible values).
+ * \param typEntity type of entities on which the solution is defined (vertices, triangles, ...).
+ *        See \ref MMG5_entities for the defined entity types. Currently only \ref MMG5_Vertex
+ *        is supported.
  * \param np number of solutions.
  * \param typSol type of solution (scalar, vectorial, ...,
  *        see \ref MMG5_type for possible values).
@@ -2009,11 +2010,12 @@ LIBMMG3D_EXPORT int  MMG3D_Set_lsBaseReference(MMG5_pMesh mesh, MMG5_pSol sol,MM
  *
  * \param mesh pointer to the mesh structure.
  * \param met pointer to the metric structure (may be NULL for an isotropic metric).
- * \param k index of the tetrahedron for which we want to get the quality.
+ * \param k index of the tetrahedron for which we want to get the quality (from 1 to
+ *        the number of tetrahedra included)
  * \return the computed quality or 0 in case of failure.
  *
  * This function returns the quality measure of tetrahedron \a k. Quality values
- * range between 0 (degenerate) and 1 (best attainable). The function returns 0
+ * range from 0 (degenerate) to 1 (best attainable). The function returns 0
  * if the tetrahedron is flat or has a negative volume, and also if \a k is out
  * of range. In the latter case it will also print a diagnostic message to
  * standard output.
@@ -2026,7 +2028,7 @@ LIBMMG3D_EXPORT int  MMG3D_Set_lsBaseReference(MMG5_pMesh mesh, MMG5_pSol sol,MM
  * >   END SUBROUTINE\n
  *
  */
-  LIBMMG3D_EXPORT double MMG3D_Get_tetrahedronQuality(MMG5_pMesh mesh,MMG5_pSol met, MMG5_int k);
+  LIBMMG3D_EXPORT double MMG3D_Get_tetrahedronQuality(MMG5_pMesh mesh, MMG5_pSol met, MMG5_int k);
 
 /**
  * \brief Get the next element of a scalar solution structure defined at vertices.