User blog comment:Sewil/Making skill page creator in java/@comment-4156018-20120730214412/@comment-259642-20120731075737

That's not how it works. Every skill has its RaceID, ClassID, JobID, TypeID, and SkillID. Whether it's Active, Passive or Supportive is not determined by the type int in the skill, but in the complete skill ID of it. The type int is just a directory to the Nexon server, the server tells the client what to do. (Eg. attack mob, heal self, heal party, etc.)

For example, 21121002. The 2 is the RaceID (Hero). The first 1 is the Class ID (Warrior). The 12 is the job ID (4th job the 1st tier). The third 1 is the type of the skill (Active). Then 002 is the ID of the skill. In Nexon's eyes, there is no Supportive skill, just a bunch of 1's and 0's which determine Active and Passive.