At this time, we have commands like sentry and guard. For me, they're the commands I hand out when I have ships just sitting there, and I don't want them doing anything else. Unfortunately, commands like sentry and guard aren't good enough for that. They can keep ships just sitting there... unfortunately their very purpose is defined by what conditions will trigger their reactivation and prompting me for instructions. The sentry command wakes up the ship when any ship (any that is not yours) comes into sensor range. The guard command works the same, except the focus is narrowed to only hostile ships (so neutral and allied ships are ignored).
Neither command are what I want. I want a command that will never automatically wake up a ship. If I give a fortify order to a ship, I want it guard the location with its life, and don't bother me with news and reports. The very fact the ship is where it is at is important to me, not what it could be doing.
I'm a fan of building sensor ships. They're ships with a large sensor radius, large enough to detect enemies far away. If possible, I would like to be able to see the locations and movements of all ships. Unfortunately, the sentry and guard commands don't work for this job. They won't activate if their conditions are within sensor range, and will wake up if something does moves into range. The current best way to make this work for me is to click the pass turn button... every turn. This obviously gets annoying real fast if I have multiple ships I would like to fortify.
Likewise, I like keeping fleets in strategic positions on the map. For instance, I might keep a few fleet somewhere between my worlds and the enemy. I put them there with enough distance from my worlds, that if those ships fail to destroy or catch hostile threats, then I have a few turns (or more) to prepare my defenses. Of course, such fleets works best with a good sensor range, and when I don't send them chasing threats that would require more than a single turn to catch. This too would work better if I didn't have to tell a ship to pass it's turn until it is time to attack.
Anyways, I'm not super attached to the name "fortify". If giving it a different name improves the odds of this being implemented, for instance calling it "hold your ground". I've been asking for such a command back when GalCiv 2 was still getting updates.