Hi, Juergen. I do not ask to specify any encoding to be sent to client. And I do not ask to specify default encoding for parsing of all markup files or for client output. I just ask to explicitly specify any encoding that you consider appropriate for Wicket built-in html files. It doesn't have to be UTF-8. It can have absolutely any value that will allow correct file reading.
I know that this encoding is used for loading only. The point is that we want to force all html files in our application to explicitly specify encoding (because platform default may [an will] be inacceptable). And in current situation we have to duplicate all Wicket htmls with addition of xml prolog.
As additional argument, you cannot be sure that all current and future encodings that can possibly be set as platform default will correctly load your html files. So explicit specifying will protect you against possible environment-specific errors.