re "Dents & Buckles Chart"
Taharbel,
There are some good answers above, but I take issue with one point - there IS a requirement that all damage (and repairs thereto) are recorded, as someone has already said. BUT dependant upon the Airworthiness Authority concerned, this record does NOT have to be in the form of the (admittedly common) "Dents & Buckles Chart". For example, JAA did not require such a chart a few years ago (check for today's regs on the JAA & EASA websites if this is your Authority); a "simple list" showing date, STA, detail of damage, SRM manual ref (if damage within limits & repair listed in SRM, or a/c manufacturer Engineering Report & local EO for specific repair if damage outwith limits) would (still will?) meet the JAA requirement.
The basic point about the "Dents & Buckles Chart" is that it is generally speaking a nice and easy way to record & understand all that's happened to an airframe, but dependant upon the Authority concerned, it does NOT have to be the form of a chart. More important is a listing of all repairs and the respective SRM/EO reference, especially if a particular repair is temporary with a time limit on it.
Krgds
AES