Usage:
   ObjectTemplate.SetSightIcon image

Argument values:

Used in object types (and how often in each type): HandFireArms (1%)

Used in one .con file: objects/HandWeapons/Binoculars/Objects.con

Example: (from objects/HandWeapons/Binoculars/Objects.con)
   ObjectTemplate.Create HandFireArms Binoculars
   ObjectTemplate.ItemIndex 5
   ObjectTemplate.MagType 2
   ObjectTemplate.NumOfMag 1
   ObjectTemplate.MagSize -1
   ObjectTemplate.FireOnce 1
   ObjectTemplate.AltFireOnce 1
   ObjectTemplate.SoldierCameraPosition 0/-0.03/0.2
   ObjectTemplate.ProjectileTemplate BinocularsProjectile
   ObjectTemplate.Projectile2Template BinocularsProjectile2
   ObjectTemplate.CreateSkeleton animations/Binoculars.ske
   ObjectTemplate.UseSkeletonPartAsMain base
   ObjectTemplate.ZoomFov 0.2
   ObjectTemplate.UseScope 1
   ObjectTemplate.FireInCameraDof 1
   ObjectTemplate.ProjectilePosition 0/0/2
   ObjectTemplate.GUIIndex 84
   ObjectTemplate.SetScopeIcon "binocular.tga"
   ObjectTemplate.SetSightIcon "scout_ring_128x128.tga"
   ObjectTemplate.SetSniperSight 0
   ObjectTemplate.HasDynamicShadow 1
   ObjectTemplate.CreateSkeleton animations/Binoculars.ske
   ObjectTemplate.UseSkeletonPartAsMain Binoculars
   ObjectTemplate.AddTemplate BinocularsLod