In my case, "+" sign get stripped out.
To reproduce :
- Have a course with an assignment and a couple of student
- Log in with a teacher user
- Go in grader report (Course administration > Grades)
- In Grade administration ► My report preferences ► Grader report, make sure you have the following options enabled:
- Quick grading = Yes
- Show quick feedback = Yes
- Enable AJAX = yes
- Turn Editing On (doesn't matter actually but made test easier)
- Add "+++" in the quick feedback field for a student
- Change page (go to the outcome report)
- Return to grader, quick feedback for the previous student will be empty
I've test a couple of characters and I found that plus sign and amperstand (&) signs get stripped out. Others, like minus, div, dollar sign, etc. are ok.