-two adjacent cells can differ (i.e. 0.3 means 30%).
-- <b>Nb. Segs per Edge</b> and <b>Nb Segs per Radius</b> - allows to define the
-minimum number of mesh segments in which edges and radiuses will be
-split.
-- <b>Allow Quadrangles</b> - allows to use quadrangle elements in a
-triangle 2D mesh. This checkbox is not present in Netgen 3D parameters
-because currently building a tetrahedral mesh with quadrangle faces is
-not possible.
-- <b>Optimize</b> - if this box is checked in, the algorithm will try to
-create regular (possessing even sides) elements.
+two adjacent cells can differ (e.g. 0.3 means 30%).
+- <b>Nb. Segs per Edge</b> - allows to define the minimum number of
+mesh segments in which edges will be split. This parameter is used
+only if <b>Limit Size by Surface Curvature</b> is checked.
+- <b>Nb Segs per Radius</b> - allows to define the size of
+mesh segments and mesh faces in which curved edges and surfaces will
+be split. This value divided by a radius of curvature gives an element
+size at a given point. This parameter is used only if <b>Limit Size by
+ Surface Curvature</b> is checked.
+- <b>Limit Size by Surface Curvature</b> - if this box is checked in,
+then size of mesh segments and mesh faces on curved edges and surfaces
+is defined using value of <b>Nb Segs per Radius</b> parameter, and
+number of segments on straight edges is defined by values of
+<b>Nb. Segs per Edge</b> parameter. If this box is not checked in,
+then size of elements is defined by three parameters only:
+<b>Max Size</b>, <b>Min Size</b> and <b>Growth rate</b>.
+- <b>Allow Quadrangles</b> - if this box is checked in, the mesher
+tries to generate quadrangle 2D mesh. Triangle elements are created
+where quadrangles are not possible.
+- <b>Optimize</b> - if this box is checked in, the algorithm will modify
+initially created mesh in order to improve quality of elements. Optimization
+process is rather time consuming comparing to creation of initial mesh.
+- <b>Fuse Coincident Nodes on Edges and Vertices</b> - allows merging
+mesh nodes on vertices and edges which are geometrically coincident
+but are topologically different.