If a teacher chooses to switch between advanced grading types, there should be some form of warning.
Create new marking guide advanced grading form type
Or should we prevent this once the grading item has been used to a particular stage?
This issue was assigned to me automatically, however I will not be able to work on this issue in the immediate future. In order to create a truer sense of the state of this issue and to allow other developers to have chance to become involved, I am removing myself as the assignee of this issue.
For more information, see http://docs.moodle.org/dev/Changes_to_issue_assignment