The full explanation of these is in a paper (.ps file) published in the Chapman Conference on Coronal Mass Ejections.
Recently J.I. Khan has found three examples of dimming signature with strikingly different characteristics: the dimming occurs in trans-equatorial loops, the subject of frequent science nuggets of this type. Briefly, he found three examples of the sequence flare => global wave => loop disruption => prompt loop reformation. Here's an example:
Although the details are not given here, this large-scale loop rises into the corona and beyond, forming the front of a beautiful CME. Unlike many CMEs, but in agreement with the early work of Richard Harrison, the CME occurs non-concentrically with respect to its flare. It should be noted that in these cases there is strong evidence that the flare caused the CME - timing, morphology, and a plausible mechanism all support this view.
These events also do not show much evidence of helical structure, which
we know to play a role in many eruptive flares and CMEs.
So if you have read this far, you understand the title of this nugget -
All of the earlier four classes of X-ray dimming events might be different
manifestations of flux-rope eruption, whereas these interconnecting loops
might be quite different.
December 10, 1999 Hugh Hudson (firstname.lastname@example.org)