Subaru 1998 Forester Owner's Manual page 278

Horizontal beam angle gauge
Center
mark
2. Look at the horizontal beam angle gauge. The center mark (the red
line on the inner scale) should not deviate from red line on the outer case
by more than two segments on either side of the gauge.
If the beam angle gauge deviates from the acceptable range, take the
vehicle to your SUBARU dealer for adjustment of the headlight aim.
10-48
Indicator
Center
mark
Acceptable
OM-H0380
Center Center
mark mark
Acceptable
HG0180