Sometimes you might need the option to allow your users to comment on FogBugz cases, without allowing them to change other parts of the case (similarly as done in other widely used issue tracking systems).
We list below a few options, but all of them are only partial solutions, due to the inherent design of FogBugz focusing on simple and easy workflow and user management.
Edit Closed Cases
Normal and Administrator users can edit closed cases, by using the Edit button.
Anything added in the editor using the Edit button will be logged on the case. This logged change will look similar to comments available on other issue tracking systems.
However, these Normal and Administrator users also have the right to Reopen the case anytime and change any of its properties (changes which, of course, will be logged on the case).
Also, any reply sent to emails sent from this case would Reopen or Activate the case, thus allowing changes to any field.
This option would be the closest to what is available in other widely used issue tracking systems.
Using Community Users
You could set up the users that you would like to restrict as Community Users.
In this case, as Community Users, they can add comments, but only on the cases they have submitted. Also, they will not be able to see comments added by Normal and Administrator users.
This option is very restrictive and requires overhead due to the community user management effort.