The mercenary missions issued by the Mercenary Alliance are also divided into levels.
Starting from the most common C-Level, followed by B Level, A-Grade, S-Level, SS-Level, and the highest, Triple-S Level!
Triple-S Level is also known as the ultimate bounty.
Generally speaking, S-Level missions require approval from the Mercenary Alliance Headquarters before they can be issued, and it's not something anyone can issue; it depends on qualifications and financial resources.
It's the same for mercenaries accepting missions. Ordinary mercenaries can take any mission below S-Level at will, but for S-Level, they must assess their strength, historical mission completion rate, and so on.
As the ultimate bounty of the Mercenary Alliance, a Triple-S Level mission may not appear for years.
Of course, there's a difference between a Triple-S level issued by the Mercenary Alliance Headquarters and one released by a division in a Star Domain.