Going through the 40 Kennedy halves that I picked up today, this is the only thing remotely exciting about these coins, except for the unusual number of nice, shiney 97, 98 and 99 P mint coins amonst the batch. This die break, if indeed that is what it is, is on a 1998 P. The mark closest to the 1 is most likely a scratch but the line that runs straight from the edge to the point of Kennedy's neck appears to be a die break to me. Do you also think so? Thanks.
lol With the previous posting of a penny with a similar flaw, I was corrected by another forum member that it was a die break, not a die crack.
Something you will find out is that not everyone uses the correct terminology when trying to describe a coin. They may be trying to say the same thing - they just use the wrong words. Some people even make up their own terms.
A "die break" refers to a die from which a piece has broken away, leaving a void in the die face. A "die crack" refers to, well, a crack in the die face.