--- /dev/null
+Changed: The many KellyErrorEstimator::estimate() overloads all have
+an argument that represents the Neumann boundary values (if the
+solution of the PDE satisfies Neumann boundary conditions on parts of
+the boundary). They used to just be of type Function<dim>, but this
+has now been changed to Function<dim,number> (or, more precisely,
+FunctionMap<dim,number>, which stores a map to Function<dim,number>
+objects) where @p number is the underlying data type of the input
+vector. In other words, if you are using a regular Vector<double> (or
+PETSc or Trilinos equivalents), then nothing has changed since @p
+number is @p double, which is the default for the Function class. On
+the other hand, if you are using a Vector<std::complex<double>>, for
+example, then you need to pass a Function<dim,std::complex<double>> --
+which of course makes sense because the Neumann boundary values of a
+complex-valued solution should also be complex-valued.
+<br>
+(Wolfgang Bangerth, 2017/11/17)