The channel re-arrangement window lets you shift the order of the channels in a file (it also allows channel duplication and channel deletion). The window shows the current channel order; you click channel-indicator buttons ('next...') in the order you desire the new arrangement to be. This image shows channel order selection in progress, with three channels chosen out of six:
A check-button lets you opt to have a suffix indicating re-arrangement appended to the file name.
NOTE: This operation is not undo-able.