xcdCurrentOperation
{
 xcoIdle = 0,
 xcoPreviewing = 1,
 xcoListing = 2,
 xcoZipping = 3,
 xcoUnzipping = 4,
 xcoRemoving = 5,
 xcoTestingZipFile = 6,
 xcoGettingInformation = 7,
 xcoConverting = 8
}

This enumeration is used by CurrentOperation property. Explanations on each parameter can be found in that property's help topic.