Updated Mission planning (markdown)

Mission-planning.md

@@ -1,4 +1,4 @@
-**Note**: The [Tips for AI Handling page](Tips-for-AI-Handling) contains advice on which AI aircraft are best for each task. The auto-planner follows priorities for the best aircraft for the job when it can, but that guide may be useful to players planning their own AI missions.
+**Note**: The auto-planner follows priorities for the best aircraft for the job when it can, but that guide may be useful to players planning their own AI missions.
 
 Each air mission is defined by a "package". A package is a group of one or more flights all working toward the same goal. The flights of the package can perform different tasks, at different times, and depart from different airports. For example, a strike mission attacking a factory will include a strike flight whose task is to attack the factory, but it can also include a SEAD flight to suppress any SAMs the package encounters, and an escort flight to protect the package from enemy aircraft.
 
@@ -18,7 +18,7 @@ Flights will have their takeoff delayed long enough that all flights can arrive
 * All other shore player flight start types will spawn immediately. Use delayed runway and air starts with caution, as there is no way to prevent the player from being spawned into the path of another flight.
 * Player flights from the boat will spawn immediately (https://github.com/dcs-retribution/dcs-retribution/issues/375).
 
-To prevent player flights from being delayed, use the "Never delay player flights" option in the campaign settings. **This does not alter your mission time. It only lets you sit in a cockpit while you wait.**
+To prevent player flights from being delayed, use the "Never delay player flights" option in the campaign settings. This is mostly useful for multiplayer squadrons where player want to go through pre-flight checks together. **This does not alter your mission time. It only lets you sit in a cockpit while you wait.** This means that it's not a way to "speed up" when you can take off. You are merely changing how you wait. If you want to generate the mission at your actual start time, use the [Fast Forward option](https://github.com/dcs-retribution/dcs-retribution/wiki/Fast-forward).
 
 When planning a mission, if you do not care specifically when the package reaches the target but instead want to plan the mission to begin as soon as possible, use the "ASAP" button next to the TOT in the package UI.
 
@@ -32,6 +32,11 @@ A join point is added after the hold point. At this point the flights will rende
 
 A split point is added after the egress point. This is where flights will split off from each other to head to RTB.
 
+## Unlimited fuel
+Turning on unlimited fuel does not mean AI aircraft will never run out of fuel, because that will make a2A refueling flights pointless. Rather, AI aircraft will have "unlimited fuel" (i.e. their fuel levels cannot drop below 40%) from start up all the way till they reach the Join waypoint. After which, they will be switched back to limited fuel all the way till they reach their Split waypoint, where unlimited fuel is turned on once more.
+
+The intent is to prevent AI aircraft from RTBing due to low fuel before they reach their ingress waypoint and complete their mission. However, AI aircraft may still seek out and land at neutral airfields while RTBing if they judge fuel levels to be too low to reach their home airfield. Unlimited fuel is turned on once again at Split so as to prevent AI aircraft from running out of fuel and falling out of the sky while waiting for landing clearance, as DCS's ATC does not have any way to prioritise landing clearance for aircraft on minimal fuel.
+
 ## Task types
 
 Below is a list of all the currently available task types for flights. More will be added in future updates.