You can grant access to the teleporter in a number of ways. Here are examples.
For this example we don't want anyone to be able to use it apart from you and your buddy. Select the PRIVATE button menu option. Now type your buddies name into the note card called "Private" inside the iTP's contents folder. That's it! Now only you and your buddy can ride the iTP while it is set to PRIVATE mode. Add as many friends as you like into the Private note card. The system will auto update. I suggest you do this before proceeding to leave copies or record locations using the iTP.
Group Only Access
If you wish to only allow people in the same group as you to teleport, choose the GROUP option from the menu. Each person will need to have the group which is set on the iTP to teleport. This also effects any private names in the "Private" note card.
In PUBLIC mode you do not have to enter any names into the note card or have it set to any particular group, as its for public use anyone can use your teleporter. Just set it and forget it.