The 2M rule is in effect for these scenaria:
1) Throwing off of the tee, your disc went deep in the woods and got caught in a tree above 2M. You elect to throw again from the tee. What are you lying on the tee before you throw again?
2) Another player throws off of the tee, deep into the woods. Said player elects to take an unplayable lie, effectively abandoning their first tee. Depending on your answer to 1), do you, as another player in the group, have the right to look for the disc to see if it above 2M?