  Several experimental groups have reported evidence for baryons with flavor
exotic quantum numbers that cannot be explained as $qqq$ bound states but
require a minimum of five quarks -- $qqqq \bar q$. These pentaquark states
include the $\theta^{+}$, the $\Xi^{--}$ and the $\theta_{c}$. The reported
widths of these new states are consistent with experimental resolution and may
be as narrow as a few MeV/$c^2$ or less. Prior to 2003, experimental searches
for flavor exotic baryons spanning several decades yielded negative results.
There have also been a number of searches carried out since the reports of
these new pentaquark states that do not confirm their existence. This review of
both the positive and negative reports seeks to understand the current
situation regarding the experimental evidence for pentaquarks.
