A Holodoc (short for holographic documentary) was a form of informative entertainment common in the 23rd century. In 2294, an incognito Montgomery Scott claimed that Spock was a famous holodoc star on par with Jacques Cousteau in order to establish a new identity for him. (TOS novel: The Fearful Summons)

The description seems to indicate these would be meant for viewing on some sort of 3V technology.