Final answer:
In the context of flare cartridge systems, a safety pin or locking device is typically installed after the flare cartridge is in place to prevent accidental ignition.
Step-by-step explanation:
The question seems to pertain to the procedure related to the installation or handling of flare cartridges, likely in a military or emergency context. After the final flare cartridge is securely in place, usually a safety pin or a similar locking device is installed to prevent accidental ignition or deployment of the flare. Every flare cartridge system may have a specific mechanism and procedure for this, often detailed in the system's operation manual or safety guidelines. Ensuring the safety device is in place is crucial for the safe handling and operation of flare cartridges.