  RHESSI observations of elementary flare bursts are presented. These solar
flare elements are distinct emission peaks of a duration of some tens of
seconds present in the hard X-ray light curves. They are characterized by
consistent soft-hard-soft spectral behavior, which can be described in a
quantitative way and compared which predictions from acceleration models. A
detailed analysis of hard X-ray images for an M5 class flare shows that
elementary flare bursts do not occur at distinct locations, but as twin X-ray
sources move smoothly along an arcade of magnetic loops. This observation
apparently contradicts the predictions of standard translation invariant
2.5-dimensional reconnection models.
