WebDAV uses Formatter.makeStringFilesystemSave() to convert group and course names to url-compatible virtual folder names. The problem is that this method does encode everything in UTF-8/URL. Therefore spaces are converted to +, umlaute are converted to %xyz etc.
As a result, the names are very confusing and often not readable. The goal of this issue is to write another method to remove/replace/encode forbidden characters so that users still recognize their courses and groups.
The same improved method should also be used on other places where the current Formatter.makeStringFilesystemSave() method is used when it it makes sense.