Flight numbering

Do you use any kind of flight numbering scheme or just sequentially? I’ve done some reading on how airlines do it in the real world, but it seems like it would be a lot of work to keep it consistent once you get into the thousands of flights a day.

just an example

100-149: Hub A, direction east

150-199: Hub A, direction west

200-269: Hub B, short-haul flights

270-299: Hub B, long-haul flights

Whats the use of it? I have 6800 flightnumbers, you cant manage them with a specific system. Just use those that are available; not specific numbers for a special hub or direction.