*
* <li> No other boundary conditions are considered.
* </ul>
- * The object describing the boundary conditions is obtained from the
- * triangulation.
*
- * Thanks go to Franz-Theo Suttmeier for clarifications about boundary
- * conditions.
+ * In practice, if you have Robin boundary conditions or are too lazy to
+ * accurately describe Neumann values, then this is rarely an issue: if you
+ * don't say anything in the map about a particular part of the boundary then
+ * the Kelly indicator will simply assume that the solution is correct on
+ * that part of the boundary and not touch it. Of course, if you have a have
+ * a Neumann or Robin boundary, that isn't quite true, there is going to be a
+ * difference between the normal derivative of the numerical solution and the
+ * Neumann values these normal derivatives should equal. So if we simply
+ * ignore those parts of the boundary, we'll underestimate the error. In
+ * practice, this rarely appears to be a problem -- you may not refine the
+ * cell this time around but you'll probably refine it in the next refinement
+ * step and everything is good again. After all, for all problems but the
+ * Laplace equation, the Kelly indicator is only an indicator, not an
+ * estimator, and so the values it computes are not exact error
+ * representations anyway.
*
*
* <h3>Handling of hanging nodes</h3>