RCA 25215RE1 User Manual page 10

Or, you can use the 2 single telephone lines plug into the 2 jacks on the back of the telephone.
Line 1
Line 2
If you have Line 1 and Line 2 wired into one wall jack in your home or office, you can use one of the supplied
telephone line cords to connect from the wall jack to the Line 1 + 2 jack on the back of the phone as shown
below.
Line 1 + 2
5. If you want to mount the telephone on the wall, you can plug the 2 lines such as the below drawing;
Line 1
Line 2
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