Security clearance
Security clearance or security verification was a level of authority given to an officer based on rank, status, and position. Computers then identified the individuals by the entry of their vocal or numerical authorization code. Alternatively, specially programmed isolinear rods entered into the computer could also allow various levels of security clearance. ()

When Lieutenant Malcolm Reed stated to the Andorian Lieutenant Talas that he "wouldn't trust his own mother" with 's weapons frequencies, Talas found it an odd expression, as Talas' mother's security clearance was higher than hers. ()

If an officer felt that they could no longer be trusted with clearance, it was possible for them to delete their own clearance, as demonstrated by Lieutenant Tuvok when he was destabilized by a mind meld with Crewman Lon Suder. ()

 had a security clearance that was considered high among her people, the Ramurans, and thus had enough knowledge that she knew how to program a vessel to detect Ramuran vessels. ()

Clearance level accessibility
pah doQ cha
 High level Klingon security clearance. Ambassador K'Ehleyr possessed pah doQ cha clearance and attempted to use it to gain access to High Council files on the Khitomer Massacre from the Klingon Imperial information net. Her access was denied because the files had been restricted to du-ko-cha clearance or higher. ()

Du-ko-cha
 High level clearance used by members of the Klingon High Council. Duras had restricted the files on the Khitomer Massacre to du-ko-cha clearance or higher. ()

Alpha Red priority
 When combined with clearance verification 9218-Black, it was an order from Cardassian Central Command to delete all records of the encounter from the logs and remain silent. ()

Level 1
 Allowed access to stations personnel and official logs. () 
 Allowed access to weapons lockers for Starfleet personnel. ()

Level 3 (and above)
 Required to access classified information regarding the  following its disappearance in the Badlands in 2371. ()

Level 4 (and above)
 Allowed access to Deep Space 9's ship-departure logs. ()
 Level required to access tactical data, including multi-vector assault mode, on the . This level was also required to access ship's communications aboard the Prometheus. ()
 Required access level for a Starfleet Intelligence officer. ()

Level 4 Alpha
 Required access level for access to an alien starship's black box on the Enterprise NX-01. () 

Level 5 (and above)
 Required access to show the station layout of DS9, while highlighting all repaired replicators on the command level. ()

Level 6 (and above)
 Access Deck 12, section 42 of Voyager around 2376 was off-limits to everyone except senior officers with this clearance or above. It was here where an electromagnetic lifeform was living in an artificial environment until a new class J nebula could be found for it to reside. ()

Level 7 (and above)
 Allowed access to weapons lockers for non-station operations personnel. ()
 In 2372, information about the Cardassian Union's granted request for replicators from the Federation Council and their transport to Cardassian planets was considered only for officers of this clearance level and above. ()

Level 9
 Required to override a Cardassian counter-insurgency program initiated during a Bajoran revolt. ()

Level 10
 This security level was for information labeled as for captain's eyes only. ()
 Required to access the Omega One data file, which contained information on the Omega Directive. ()

Priority 3
 Required to release information on a starship's defense and navigational systems. ()

Sigma 9
 Required to release specific classified documents on the morphogenic virus from Starfleet Medical. ()

Personal clearance levels
Alpha 1
 Data ()

Alpha 2
 Jean-Luc Picard ()

Level 1
 Miles O'Brien ()

Level 3
 Wesley Crusher: access to the Custodian on Aldea. ()
 Harry Kim (at least) ()

Level 4
 Julian Bashir (at least)
 Jadzia Dax (at least)
 Worf (at least) ()

Level 4 Alpha
 Jonathan Archer 
 Malcolm Reed
 T'Pol () 

Level 6
 Odo ()

Level 7
 Quark (acquired/stolen) ()
 Michael Eddington
 Jadzia Dax 
 Kira Nerys
 Odo
 Benjamin Sisko
 Worf ()

Level 9
 S.G. Dukat ()
 Kathryn Janeway ()

Level 10
 Kathryn Janeway ()

Level Red
 Voje ()

Priority 3
 Data ()

Sigma 9
 Benjamin Sisko ()

de:Sicherheitseinstufung
Computer technology
Security