\listfiles \documentclass{article} \usepackage{ginpenc} \usepackage[latin1]{inputenc} \usepackage[english,ngerman]{babel} \usepackage{makeidx} \makeindex \providecommand\inputenc{??} \begin{document} Please have a look into the file \jobname.idx. Here, the entry written in German should be typed with \verb|"u| while the English version is typed with \verb|\"u|. \typeout{\languagename:} \typeout{* Input encoding: `\inputenc'} \index{Rüber (ger)} \inputencoding{cp850} \typeout{* Input encoding: `\inputenc'} \inputencoding{latin1} \selectlanguage{english} \typeout{\languagename:} \typeout{* Input encoding: `\inputenc'} \index{Rüber (eng)} \inputencoding{cp850} \typeout{* Input encoding: `\inputenc'} \printindex \end{document}