Need Help Plz

[watzmann]

have a circuit Diagram it's for a telephone to indicate is it in use or not .

i want to make this circuit , but my problem is :

the circuit have it's input as two terminals , 1- Ring 2- Tip

i don't know what the terminal Tip mean ,
how can i find it on the telephone board , anywone can help

Thank you

[linear1]

Looking at the wiring in the phone jack, ring is the red wire, tip is green.

If you touch both at the same time, you'll get a good zap. There's about 48VDC between those two wires.