On reddit, a mod can modify the permissions of someone further down on them on the list.

    Foo
    Bar
    Qux

Foo can modify the access for Bar or Qux. Bar can modify Qux's access.

Only Reddit can modify the access for Foo.

If a new mod is added (Xyzzy), they are added to the bottom of the list.

    Foo
    Bar
    Qux
    Xyzzy