Thanks for your advice so far. I am currently testing the solution with utf8::upgrade and Encode::_utf8_on .

Unfortunately there is at least one popular German webspace provider still running Perl 5.6 without Encode module. I phoned them this morning and requested them to install 5.8 as soon as possible. I also tried to save the script itself in UTF-8 (at the other provider which uses 5.8.0), but Apache (1.3.27) complained with an "internal server error" despite use utf8; in my script.

My original intention was just to use UTF-8 to make my (and my company's) scripts more versatile, but I have been quite disappointed to learn that certain components and institutions seem not to be ready for internationalization yet.

Anyway, after all the time I already spent testing, I will hopefully end up with a working solution.