Just about anything ever. Any random, strange, or otherwise unexplanable occurance. The be all and end all of words.
\"Hey, that cinco-dog over there is a dongle.\"
\"The car looked very much like a dongle.\"
\"Dongle that\" (replaces a certain four letter \'f\' word)
Originally used as a bridgepoint term between the terrorist puppets and the increasingly hilarious Team of the Americas, \'Derka Derka\' has since transcended such lowly usage.
Nowadays, it is not uncommon to hear the phrase in relation to a missed quotation. Such as \"She said, \'Derka Derka\' and then left.\" It can also be used in conjunction with the equaling transcendent term, \'Gagahgagahgahga,\' which, in and of itself, is related to the drunkeness associated with severe exhaustion.
Ideally, Derka Derka can be used in any situation.
\"Derka Derka, Gagahgagahgahga\" (when sleepy and trying to express that notion)
\"So she said, in a manly voice, \'Kris, I want some food. Derka Derka.\' and left him to his task.\"