Hidden Helper T quests

Available Hidden Helper T Quests can bee see in the "Quest List" panel. There is a total of 81 quests available, numbered 001 to 081, skipping 050 for an unknown reason. Visit the Hidden Helper to accept a quest and to receive your reward upon completion.

Each quest has certain requirements to be met before being able to start: Example - Hidden Helper T (No.001) requires Level 36 and Class Rank 3. A level 45 character with Class Rank 2 won't be able to see the quest yet.
 * Character Level
 * Character Class Rank (achieved upon completion of Level Up quests).

Dungeon Training Card quests
There are 12 additional "Dungeon Training" quests which require a D.T. Card in your character's inventory for the quest to appear. If you have a card in your inventory, for which you have not yet completed Hidden Helper T Quest, re-log with the DT Card in inventory or move to warp zone or another town and the quest should appear.

Credits
Credits go to moomooo on the Cabal Online forums. Source: http://forum.cabalonline.com/showthread.php?p=219532