Uwe Baumbach wrote:
Hi there,
is there a ready to use way to prevent file upload without an assign licence?
We do not want preload some "common" licence but offer a blank choice and force an input (selection from the list).
Well, you can provide a license-dropbox like the one used at commons: http://commons.wikimedia.org/wiki/Image:Commons-upload-screenshot.gif
Can we avoid source changes?
What do you mean? Blocking the image file from editing or the file for reuploading? Both should be possible (the later may require a small change in upload code). But the original text will be always shown... that's why wikis hava a history after all.