Traditionally, non-ASCII characters have been an issue for XML formats like HR-XML Resume. Characters such as é, ß, or © required the user to type the special codes é, &eszlig;, and ©, respectively.

These special codes are not necessary. As long as your editor supports Unicode and is able to save XML files in the UTF-8 encoding, you can simply enter the extended characters directly into your editor. They will show up correctly in the final CV or résumé.