Pinning & the ignore list
Two tools keep the chain stable and uncluttered.
Pinning
When a connection is deleted, the app tidies up after it: if a system is left with no connections at all, it's removed automatically so dead-end nodes don't linger. Pinning a system switches that off — a pinned system stays on the map even when nothing connects to it any more.
Pin your home, your staging, and any system you want to keep regardless of what happens to the chain around it.
The ignore list
Add a system to the map's ignore list and mapping as you fly will never add it. This is ideal for systems you pass through constantly but don't want cluttering the chain — trade hubs and common waypoints. Remove it from the list later and it can be mapped again.
The list does double duty: the router steers around ignored systems too, for everyone on the map, and so do the Discord route command and the proximity and killmail alerts. A system already placed on the map stays reachable, and a jump into it is still recorded.
The list is the map's, so it takes a manager to change it. Find it under Settings → Routing, or right-click a system on the map and choose Ignore for everyone from the route planner menu. Everyone else can read the list, which is worth a look when a route seems to take the long way round.
This is separate from the route planner's own ignore link, which steers just your routes around a system for as long as you keep the map open on this device.
Together, pinning and the ignore list let you decide exactly what belongs on the map: keep what matters, and keep the noise out.