I have a few questions.

1. Was "JB" not available?

2. How many 2 letter/digit airline codes are possible?

(26 alphabets x 26 alphabets) + (26 alphabets x 10 digits) + (10 digits x 26 alphabets) ?

3. Anything beyond just the 2-letter/digit codes that is used for commercial flights?

4. Do they get recycled?

5. If the airlines have some ability to choose their designator, can they buy the rights for a certain designation from another airline, including defunct carriers?