Antenna Tilt
The Antenna Tilt is for adding or removing mechanical antenna tilt. Some antennas have electrical tilt which should be included in the antenna pattern, so you will not need to enter anything other than zero here. However, if your antenna has a physical tilt to it, you need to enter the correction here.
Negative values here are for downward tilt, any positive values are for upward tilt.
For example, your antenna has 2° of down tilt, then you will need to enter a -2, or negative two.-2.