CTO SeaDogs
Significant Changes in the Navy Ratings Structure in 2005 and 2006.
DT - Dental Technician
Disestablished 01 Oct 2005.
Merged into the HM - Hospital Corpsman rating.
PS - Personnel Specialist
Established 01 Oct 2005
PN - Personnelman
Disestablished 01 Oct 2005
DK - Disbursing Clerk
Disestablished 01 Oct 2005
PN & DK ratings merged into the PS rating.
ND - Navy Diver
Established 01 Jun 2006 thru 01 Oct 2006
Source: Divers in various ratings designated by NECs 5311, 5341, 5342, 5343 and 5346.
EOD - Explosive Ordnance Disposal Technician
Established 01 Jun 2006 thru 01 Oct 2006.
Source: EOD technicians in various ratings designated by NECs 5332 thru 5337.
MC - Mass Communications Specialist
Established 01 Jul 2006
DM - Illustrator Draftsman
Disestablished 01 Jul 2006
JO - Journalist
Disestablished 01 Jul 2006
LI - Lithographer
Disestablished 01 Jul 2006
PH - Photographer's Mate
Disestablished 01 Jul 2006
DM, JO, LI & PH ratings merged into the MC rating.
CTO - Cryptologic Technician (Communications)
Disestablished 01 Oct 2006
Merged into the IT - Information Systems Technician rating.
SB - Special Warfare Boat Operator
Established 01 Oct 2006
Source: Personnel in various ratings designated by NECs 5350 and 5352.
Warfare designation: SWCC (Special Warfare Combat Craft)
SO - Special Warfare Operator
Established 01 Oct 2006
Source: Personnel in various ratings designated by NECs 5320, 5323, 5326, 8491 and 8492.
Warfare designation: Navy SEALs (Sea, Air & Land) 
