The Blu-Ray remastered version of Measure of a Man includes a number of screenshots that appear to give some idea of the top-level departments in Starfleet: STARFLEET REGULATION 02-0933-3462F PER REFERENCE (THETA), THE COMMANDING STARBASE ADMIRAL MAY, WITHIN AUTHORIZED STRENGTHS, TRANSFER ANY COMMISSIONED OFFICER FROM THE STARFLEET DEEP SPACE EXPLORATORY CORPS*, THE STARFLEET DIPLOMATIC SERVICE^, THE STARFLEET SCIENTIFIC CORPS, THE STARFLEET OPERATIONAL SUPPORT COMMAND, STARFLEET ACADEMY, AND THE DAYSTROM INSTITUTE AND APPOINT THE OFFICER IN ANY OF THE OTHER STARFLEET SERVICES. THE TRANSFER MUST BE WITHIN THE AUTHORIZED STRENGTH LIMITATIONS OF THE GAINING STARFLEET SERVICE AND MUST BE, BY MUTUAL AGREEMENT OF THE TWO DEPARTMENTS, IN THE BEST INTERESTS OF THE UNITED FEDERATION OF PLANETS INTERSERVICE AND INTERDEPARTMENTAL TRANSFERS WILL BE DISAPPROVED IF EITHER THE GAINING OR LOSING SERVICE DOES NOT CONCUR. IF AN OFFICER ENTERS ON DEEP SPACE SERVICE AND IS SUBJECT 10 PLACEMENT ON THE DEEP SPACE DUTY LIST, STARFLEET PERSONNEL MAY, WITH THE OFFICER'S CONSENT OR WITH THE OFFICER'S REQUEST, ANY TIME TO THE CONVENING OF THE STARFLEET COMMAND OR STARBASE SELECTION BOARD, DEFER THE OFFICER'S ELIGIBILITY FOR CONSIDERATION IN THE ZONE OR ABOVE ZONE FOR PROMOTION BY ANY DEEP SPACE CORPS* SELECTION BOARD. STARFLEET REGULATION 02 0933 3459C REQUESTS FOR STARFLEET EXPLORATORY CORPS* PERSONNEL TO PERFORM DUTY WITH OTHER STARFLEET DIVISIONS WILL BE ADDRESSED TO THE CHIEF OF STARFLEET OPERATIONS OR TO THE COMMANDER OF THE REGIONAL STARBASE WITH AUTHORITY OVER THE OFFICER'S SERVICE REGION REQUESTS MUST INDICATE THE BILLET DESCRIPTION, NUMBER, GRADE, LENGTH OF TOUR, AND SPECIAL QUALIFICATIONS DESIRED. UPON APPROVAL OF THE REQUEST. THE CHIEF OF STARFLEET PERSONNEL WILL BE RESPONSIBLE FOR ANY ADDITIONAL LIAISON REQUIRED IN CONNECTION WITH THE ADMINISTRATION AND PERSONNEL MATTERS AFFECTING SUCH MEMBERS THIS ACTIVITY WILL NORMALLY BE LOCATED IN CLOSE PROXIMITY TO THE REQUESTING AGENCY AND IS HEREINAFTER REFERRED TO AS THE ADMINISTRATIVE COMMANDER THE ADMINISTRATIVE COMMANDER IS RESPONSIBLE FOR CUSTODY AND MAINTENANCE OF THE OFFICER'S SERVICE RECORD, DISSEMINATION OF STARFLEET DIRECTIVES, AND ISSUING INSTRUCTIONS AND APPROPRIATE FORMS FOR REQUIRED STARFLEET REPORTS. THIS ARTICLE DOES NOT PERTAIN TO ADMINISTRATION OF STARFLEET OFFICERS ASSIGNED TO INTERSTELLAR STAFFS, JOINT STAFFS, OR PLANETSIDE STAFFS. *It seems likely that the differences between these names is either an error or the "Deep Space (Exploratory) Corps" is a sub-command of Exploratory Corps rather than a separate service. I would further assume that most of the hero characters in Star Trek have been members of this command (TrekLit id's this as UESPA, but may be a UESPA-Andorian Guard hybrid) ^This is likely most R & D, but may act as the Starfleet Liasion department for civilian research projects, extra-UFP and non-Starfleet scientific organisations like the Hansen's 'Find the Borg' mission, the duck-blind teams in Who Watches the Watchers and Insurrection, and the Vulcan Science Directorate and Vulcan Exploratory Group. Does this seem plausible?