Help! What does "L" mean in scheduling?

I am having difficulty with the scheduling. When I look at flight operations , sometimes I get 12345 - meaning monday thru friday, other times I see "l l l l l" - what the hell does that mean?  Someone please tell me. Im new, and have 6 planes, it's "Jet North America"  thank you.

L stands for Late, this means that the plane is unable to reach it's destination as it has arrived there late and there are no other avaliable slots so therefore it is forced to  turn back therefore altering the schedule 

Please stop posting non sense.

L in scheduling means the flight number is assigned to the aircraft but the flight plan of the aircraft of which that flight number is part of, is not activated or is locked.

It means that even though you have scheduled the flights and possibly assigned it to a plane, you have not yet activated the flight schedule. You have to go to the scheduling page and activate those schedules so that they can become active. The 'LLLLLLL' you see in scheduling simply means that the schedule has been established but not yet approved by you for commencement - remember, ...you are a CEO!!

Once the flight plan for the aircraft is activated (by you), the LLLLLLL will change to the actual days of the week that the aircraft operates the flight.  As I don't have any irregularly scheduled flights right now, all of my scheduled flights read "1234567" instead of "LLLLLLL".  If a flight didn't operate on Thursday, it would read "123_567" (Monday = 1)

What does S means then?

I have some problems. I cancelled a route in fleet scheduling page, they are gone in the original plane, but then when I want to add back in another aircraft, i cannot find it in the existing flight number section? Is it a bug or what?

S means the flight is scheduled but without an aircraft assigned to it. Meaning, there's a speed override set for the given day.