|image 1: obverse and reverse of the coin|
This is my 3-in-1 error Malaysia coin. Capped die, brockage error and die crack in uncirculated condition.
1. Capped die
A capped die is caused when a struck coin sticks to the upper hammer die. Once the coin is stuck to the die face, the reverse of the struck coin becomes the new die face. When the next blank is fed into the collar and the strike occurs, the reverse design of the adhered struck coin impresses itself into the new blank. This struck coin is a brockage strike. The coin adhered to the upper die is known as a die cap. This process repeats itself as more coins are struck by the cap. The greater the number of strikes, the higher the cap metal will be pushed around the upper die shaft. Eventually, the cap brakes away from the die in the shape of a thimble. coinfacts.com
brockage error can only occur when there are two coins involved. One of the coins involved will always be a struck coin which has not ejected properly. That struck coin will find its way back between the dies and will be struck next to a blank planchet which was fed into the collar. The image of that first struck coin will be impressed into that side of the blank planchet. The result will be a second coin which has images of the first coin impressed into it. Those images will be pressed into the coin and the image will be in reverse. This incuse sunken image is known as a brockage. coinfacts.com
3. Die Crack
A die crack is a mark appearing on a coin, usually in the form of a fine raised line or small blob. This happens because the coin die which struck the coin had a crack or small break in it that got transferred to the planchet during striking. coins.about.com