I've been around longer ...
anyway here is the answer that applies to most forums
1. They need another mod
AND
2. You have contributed to the well-being of the site (that is, you are a valuable member and have the respect of the other members and the staff)
AND
3. You act in a mature manner and could handle the pressure of moderation
AND
4. You know the rules perfectly and when to apply them
AND
5. Visit every day and read and evaluate every post, even the boring ones
AND
6. Most importantly, never ask or hint. Never nominate someone. It's invitation only.
For new forums, it's completely different. They will usually say first x members can be mods. The admin can kick the bad ones out later after the site is established.
Hope that answers your question, spaceduk.