allows service consumers to reserve an SSR code for manual assignment later on (i.e. manual assignment by using the Operation setSsr, see section 3.7.4), and to clear such code from display in the whole OPS sector.
An SSR code reserved for manual assignment is not available for automatic assignment. The SSR code will be re-served during a design parameter time and then released if not manually assigned to any flight plan or released according to the standard release rules if manually assigned to a flight plan during this design parameter time.
Real World Effect
The management of SSR code does not have a direct real-world effect. Its effect is reflected via the aforementioned management of correlation when the SSR code is communicated to the aircrew.