vadding

vadding /vad'ing/ n.  [from VAD, a permutation of ADV
   (i.e., {ADVENT}), used to avoid a particular {admin}'s
   continual search-and-destroy sweeps for the game] A leisure-time
   activity of certain hackers involving the covert exploration of the
   `secret' parts of large buildings -- basements, roofs, freight
   elevators, maintenance crawlways, steam tunnels, and the like.  A
   few go so far as to learn locksmithing in order to synthesize
   vadding keys.  The verb is `to vad' (compare {phreaking}; see
   also {hack}, sense 9).  This term dates from the late 1970s,
   before which such activity was simply called `hacking'; the older
   usage is still prevalent at MIT.

   The most extreme and dangerous form of vadding is `elevator
   rodeo', a.k.a. `elevator surfing', a sport played by wrasslin'
   down a thousand-pound elevator car with a 3-foot piece of
   string, and then exploiting this mastery in various stimulating
   ways (such as elevator hopping, shaft exploration, rat-racing, and
   the ever-popular drop experiments).  Kids, don't try this at home!
   See also {hobbit} (sense 2).