There aren't that many solutions. You can go to 5 digit numbers, or use 4 charac...

ComplexSystems 5 months ago | parent | context | favorite | on: Airlines are running out of 4-digit flight numbers

There aren't that many solutions. You can go to 5 digit numbers, or use 4 characters with an expanded alphabet, or do nothing. What other solutions could there possibly be?

JCharante 5 months ago [–]

Change the way you use the numbers