Further to http://www.airwaysim.com/forum/index.php/topic,46221.msg258523.html#msg258523
Not a request for the system to generate more icons like that automatically. But a request for a handful of different icons for the player to be able to assign to a route, which then shows up in route planning.
My own detailed planning gets done in notepad, the ability to add some shorthand to the route planning page would make updating that planning a lot les tedious, involve a lot less clicking of multiple routes to recheck things, find space, etc.
Personally, I'd use icons for things like:
1: Ignore this route (no demand, alliance mate on it, stupidly short runway issue, etc)
2: Check back later/fly if desperate (demand for half a flight, or lots of comp, so a flight now won't be great, but might be a lot better in 12 months. Or you've capped the tickets sold and need to change the cap as demand grows.)
3: full route
4: high priority (needs more flights, needs a flight because competitor has one and I don't, stuff like that)
5: night flight (pretty full, but space to jam in one more at certain times of day, particularly overnight)
6: Redeye (This route supports a redeye flight, or a partial one.)
No doubt other stuff that I could come up with, other stuff other people would use them for. Like a note that it's got a badly sized plane that needs replacing. Or a slot issue. Or a missing day thanks to A-check that you want to fill from another plane when you can. Or it's one you need to make sure you manually reset prices for after a global price change. etc, etc.
All it would need would be a few distinctive icons that we can assign to the route planning page. Just like flagging an existing route, only with a bit more depth beyond yes/no, and for route planning rather than the existing route summary.