-<li>if it is necessary to convert a standard mesh to quadratic or a quadratic
-mesh to standard. Note that the choice is available only if the selected mesh
-(or sub-mesh) contains both quadratic and linear elements, else the
-direction of conversion is selected automatically.</li>
-
-<li>if it is necessary to place medium nodes of the quadratic mesh on the
-geometry (meshed object). This option is relevant for conversion to
-quadratic provided that the mesh is based on a geometry (not imported from file).</li>
+<li>If it is necessary to convert a linear mesh to quadratic or a quadratic
+ mesh to linear. **Convert to bi-quadratic** creates some types of quadratic
+ elements with additional central nodes: TRIA7, QUAD9 and HEXA27
+ elements instead of TRIA6, QUAD8, and HEXA20 elements
+ respectively.</li>
+<li>If it is necessary to place **medium nodes** of the quadratic mesh **on the
+ geometry** (meshed shape). This option is relevant for conversion to
+ quadratic provided that the mesh is based on a geometry (not imported
+ from file).</li>