How to make nametags only visible when the soldier is visible?

renderer.drawNametags 1
nameTags.MaxEnemyDistance 20
NameTags.EnemyTagFadeInTime 999
NameTags.EnemyTagFadeOutTime 1
NameTags.EnemyTagDelayTime 999
NameTags.EnemyDotLimit 0
NameTags.maxFriendlyDistance 100
NameTags.manDownFadeOutTime 300

Is there any option here?
What is EnemyDotLimit for?