compatibility between Mac and PC

[Reinhold Venzl-Schubert]

Hi!

For to share my stacks build on a Mac with a PC I want to detect 
incompatible charakters in an input-field to avoid them.

1. Which are the incompatible charakters? I know "ä,ö,ü,ß". Are there 
some more?

2. Do anybody can give me a script to detect those charakters in a 
field?

Thanks
Reinhold