Fleet saving
Fleet Saving is the act of sending your ships away so they can't be hurt by enemies. An example would be sending your entire fleet on a harvest mission to a planet 4 hours away. The round trip will take 8 hours, thus keeping your fleet safe while you sleep.
Another method of fleet saving is to do a transport or deploy between your colonies. If loaded up with resources, a deploy also makes for a good way resource save too. A transport can also be used, but your fleet will deposit the resources at the target leaving them vulnerable for half of the time.
In Starfleet Commander, fleet saving is very important. A player with a Dionysus Class Recycler has strong incentive to find people who left their ships parked on a planet with little defense, destroy them all, and then harvest the debris.
This tactic can also be employed when you see a large attack incoming. At the last minute, you can load up your entire fleet (and add cargo to help resource save too) and deploy them somewhere, only to recall after the attacker lands on your home world.
