PHPUnit tests provided. Assuming the following: You have a course that has an assignment The assignment should have the Feedback comments setting enabled. You have a student that has submitted the assignment Testing instructions - for export functionality(w/ openDoc, plain text, xls and xml) Login into as the teacher/admin Go to the course and click on the assignment  Grade the assignment from the student providing a combo of text and image/audio/video link with files stored on the server and not imported into the server and save Go back to the assignment and export the gradebook with feedback You should get a file with the img/audio/video links stripped and should only contain the text components from 3 Confirm that there's no markup (from the debugging message i.e. "Before calling format_text(), the content must be processed with file_rewrite_pluginfile_urls()"  ) on the exported files Confirm that the URLs in the feedback comments point correctly to the files.