This test requires administrator access and five student accounts.
1) Create a forum and in the Subscription and tracking section, select 'Optional' from the subscription mode.
2) Create two discussions in this forum.
3) As student1, subscribe to discussion 1 by clicking the dot icon to the right of the discussion

4) As student2,subscribe to discussion 2
5) As student3,subscribe to the forum
6) As student4,subscribe to the forum and unsubscribe from discussion 1
7) As student5, subscribe to the forum and unsubscribe from discussion 2
8) As admin, backup the forum including user data
9) Restore the forum.
10)For each of the users above, confirm that the subscription data was copied over correctly