apache (and mod_dav).
It seems many WebDAV clients send filename in its platform-local
encoding. But since mod_dav expects everything, even HTTP request
line, to be in UTF-8, this causes an interoperability problem.
I believe this is a future issue for specification (RFC?) to
standardize encoding used in HTTP request-line and HTTP header,
but life would be much easier if mod_dav (and others) can handle
various encodings sent by clients, TODAY. This module does just that.