/*!
\page free_borders_page Free borders
\n This mesh quality control highlights 1D elements (segments)
belonging to one element (face or volume) only.
\image html free_borders1.png
In this picture the free borders are displayed in red. (Faces are
explicitly shown via Display Entity menu as all elements but
segments are hidden upon this control activation).
See Also a sample TUI Script of a
\ref tui_free_borders "Free Borders quality control" operation.
*/