@OP:
Usually the admin/mod team (not DIGIT), evaluate members based on certain criterion and decide, some factors are, but not exhaustive:
1. Requirement for a MOD - in a section.
2. Knowledge the person has for (1) -- section.
3. How well the person posts, in terms of TDF rules.
4. Past history in terms of behavior with fellow users.
5. Useful contribution, in terms of guides and "help" threads.
6. Personal maturity.
The person is asked, and ADMIN change the user class. Usually it is RED (section) and then a gradual graduation to GREEN (global).
End of the day, we will ask you.
CLOSING, cause this will move to troll-fest and grow to 20 pages over night.