Clipped Planchet
    A clipped planchet error is essentially an incomplete coin, missing 10%-25% of the metal, resulting from steel rods used to punchout blanks from a metal strip overlapping a portion of the strip already punched. The example below combines an off center strike along with a clip.
1892/12% off center to 4:30/10% Clip at 9:00/AU-50
1909-S struck-through NGC MS64RB.
Struck-through errors occur when foreign objects fall between die and planchet during striking. 
Pieces of cloth, metal fragments, wire, slivers of reeding, grease, oil, dirt, wire bristles (from wire brushes used to clean dies, resembling staples), die covers and other objects may fall between the dies and the coin. The most collectible struck-through errors are those with the foreign object still embedded in the surface 
    A uniface error occurs when one planchet adheres to another, resulting in each being struck by only one die. Like broadstruck errors, the coin will usually be larger in diameter than normal due to the additional pressure caused by two planchets filling the collar. 
1907 obverse uniface NGC AU50
Split After Strike
    Not to be confused with the above uniface, a split after strike error splits parallel to the faces of the planchet after the strike has been imparted. Probably due to a poorly mixed alloy, they're rare in general and extremely rare in the Indian cent series. Besides the planchet striations of the blank side, the obvious differences from the uniface are the coin's normal diameter and thinner depth.