This is a write-only trigger object: writing the value save(1) commits the router's current running configuration to non-volatile flash storage. Because cdd564Reboot explicitly does not save configuration first, this object is the only way to make in-memory changes (like a new Rx frequency or LNB power setting) survive a power cycle, so skipping it after a config change means the next reboot reverts everything. A typical workflow is: set a new receive frequency, verify the link locks, then SET this object to 1 so that value is still in effect after the unit is power-cycled during a maintenance window.