Each class has a set of Class-Specific Skills and a set of General Skills that they may learn as they level and then train up using TP. Elite Skills are a set of Class-Specific Skills, learned every 5 levels starting at 15, that are unique to particular class combinations. A character with both the Warrior and Rogue classes, for instance, has different Elite Skills than a character with the Mage and Scout classes, and a Mage/Scout has a different set of Elite Skills than a Mage/Priest.
both classes must be at the level for the elite skill. If you have a mage/priest with the mage at level 25 and priest at level 15 you will only be able to learn the level 15 elites. You will be able to learn the level 20 and 25 elites when you get the priest up to level 20 and 25.
Regardless of the name, Elite Skills are not necessarily powerful, must-have skills. They are moderately difficult to learn, however, and help to further differentiate dual-class character experiences. All Elite Skills are Class-Specific, but you can learn both sets as long as you supply the materials for certificates to an Elite Skills Master while having the necessary class set as your primary.
 How to Learn Elite Skills
In the Coast of Opportunity and Xaviera areas, you will come across quests that reward an Old Bag -
these quests are infinitely repeatable and usually require you to use special abilities to achieve an objective.
Upon opening the bag, if both of your class levels are sufficient to learn a new elite skill, you will receive a Lv. X Elite Skill Certificate. (Lv. 15, Lv. 20, etc.)
These certificates can be turned in at Lowen Dunlit in Coast of Opportunity in Heffner Camp to learn the skill for your primary/secondary class combination.