Staff officer

A staff officer is a Starfleet officer that provides specialized support to line officers and all other persons in the organization. The staff officers of a specific vessel or institute together form a senior staff. These officers hold seniority positions in their departments, but are not necessarily senior officers. Members of the senior staff are sometimes referred to by the title "Department Head". 

Senior staff positions
The following positions can be considered as senior staff positions:
 * Commanding officer
 * Executive officer
 * Second officer
 * Third officer
 * Chief communications officer
 * Chief science officer
 * Chief medical officer
 * Chief helmsman
 * Chief navigator
 * Flight controller
 * Chief engineer
 * Head counselor
 * Chief tactical officer
 * Security chief
 * Chief operations officer
 * Strategic operations officer
 * Intelligence officer
 * Chief of operations
 * Head stellar cartographer

参謀 Officier d'état-major