Vice Marshal is a military rank typically associated with members of a starfighter corps, most notibly the Imperial Starfighter Corps.
In Imperial Service Edit
In the Imperial Starfighter Corps, a Vice Marshal usually held a command staff position assisting a Marshal or higher. There usually was no specific command posting but normally were found leading a starfighter command. A typical command would consist of at least four groups depending on the task force assembled. At a minimum, a command had 1152 ships, 1920-4800 officers, and 2880-8640 enlisted. They were addressed as Marshal. If appointed as a staff officer they would act as an assistant to a Marshal.