It is stored in a system table. I propose to define a new database table where each record defines a grading system. No other notifications are sent. Some attention was paid to the layout of overviews. They are kept as concise as possible, with the relevant parts sticking out.
Relevant information is presented at the highest possible level in the page tree.
In general the system will only present users with options that can be expected to succeed. Some presentations and operations only make sense if the system is used in the suggested manner. For instance, a PC chair can't delete a track if papers have been submitted to that track. PC chairs shouldn't fiddle with the tracks after the site is opened for submissions. Still, the system presents the PC chair with the option.