Lock/Unlock tab

The Lock tab prevents any changes from being made to the Petra project's map projection. This lock can also be password protected.

Locking the map projection saves the currently selected map projection, so be sure to have the correct map projection selected before locking the project.

Lock Map Projection	Locks the map projection. A locked map projection prevents changes to the quadrant correction, datum, coordinate system, map rotation, and map XY units. It's still possible to change the import datum for correcting different reference datum-created LatLon data, as well as change the default depth units.
Password Protect Lock	Brings up additional dialogue boxes confirming that you want to add a password and then to actually create and confirm the password.