Khadgar's Unlocking was a spell for the mage designed to unlock chests and other items, in a similar manner to Lockpicking. It was removed from the beta of World of Warcraft classic.
In The Last Guardian, Khadgar was described as quite the daring student while he was a younger Dalaran pupil, often infiltrating libraries to learn about arcane knowledge. He later managed to sort out the Guardian's Library, unlocking many of its trapped books. The Khadgar's Unlocking spell was created in honor of this detail of the archmage's background.
[Tiny Bronze Key]
[Tiny Iron Key]
[Tiny Copper Key]
[Tiny Silver Key]
Patch 0.9 (2004-08-17): Removed. 