Final answer:
Talking is permissible within a formation when the command 'At Ease' is given. This allows individuals to relax and talk, but they must stay in their positions unless the command 'Fall Out' signals dismissal from the formation.
Step-by-step explanation:
While you are in formation, talking is permissible under the command 'At Ease'. The commands given in military drill and ceremonies context each have specific significance. 'At Attention' is a command for silence and immobility where you cannot move or talk, 'Parade Rest' is similar to attention but with a more relaxed posture, yet still not allowing talk. 'At Ease' allows individuals to relax and move however they cannot leave ranks. Finally, 'Fall Out' is a dismissal from the current formation, in which you can leave and talk freely. When a formation is given the command 'At Ease', members may relax in their position and are permitted to speak unless specifically ordered otherwise by their commanding officer.