  Six years ago, the discovery of Rotating Radio Transients (RRATs) marked what
appeared to be a new type of sparsely-emitting pulsar. Since 2006, more than 70
of these objects have been discovered in single-pulse searches of archival and
new surveys. With a continual inflow of new information about the RRAT
population in the form of new discoveries, multi-frequency follow-ups, coherent
timing solutions, and pulse rate statistics, a view is beginning to form of the
place in the pulsar population RRATs hold. Here we review the properties of
neutron stars discovered through single pulse searches. We first seek to
clarify the definition of the term RRAT, emphasising that "the RRAT population"
encompasses several phenomenologies. A large subset of RRATs appear to
represent the tail of an extended distribution of pulsar nulling fractions and
activity cycles; these objects present several key open questions remaining in
this field.
