Holographs

Imperium Portal

A Holographs (also - Holographis lasers or sky-writers) used to project pictures or words onto a cloud cover, that can be seen by all troops. Holographs used to declining enemy morale, reminding about past defeats, promising comfort for deserters etc.^[1]

Source

• 1: Warhammer 40,000: Rogue Trader. pg. 98