The Teacher role can add assignments and grade them; the Non-editing teacher role can't add assignments, but they can grade them or edit the grades. Sometimes however, there is a need for a role which can view assignment grades (or other) but not actually allocate grades or modify them.
The Grade viewer role - which might just as easily be called the Moderator role, Inspector role or Facilitator role - is a custom system role giving a user access to any course to view the grades but not do anything with them. Typically, you might want to give this role to a visiting exam board moderator who needs to verify student assignment grades but cannot obviously change them. A regular teacher would see the assignment grades like this:
A user with the Grade viewer role would see the same screen like this:
Please try out the role and feel free to add improvements where you feel they would be useful