DO

1. Daily Orange (Syracuse University student newspaper; New York)
2. Dam Ouachita
3. Dark One (Wheel of Time series)
4. DASH AND ONE
5. Data Object
6. Data Out
7. DAVID OKING
8. David Orozco
9. Dawson and Oberman (plasmas)
10. Day Off
11. DCS/Operations
12. Deciding Official
13. DECIDING OFFICIALS
14. Defense Order
15. Defined Order
16. Delivery Order
17. Demi Official
18. Denominacion de Origen (general identification for Spanish wines)
19. denuded oocytes
20. Departmental Offices
21. Deportation Order
22. Deregistration Official
23. Deregistration Officials
24. Describe any ODC
25. Design Objective
26. Design Overview
27. Designated Official
28. Designating Officials
29. Desk Officer (NYPD)
30. Desktop Originator
31. DESTINATIONALL OCONUS
32. Detention Officer
33. Determination Order (workers compensation claims)
34. detrusor overactivity
35. Development Officer
36. DFAS-CL OR
37. Diário Oficial (Official Gazette; Brazil)
38. Diatomic Orbital
39. Diffractive Optics (camera lenses technology)
40. Digital Orthophoto (FEMA)
41. Digital Output
42. Diode Outline
43. Diploma in Orthopaedics
44. Direct Object
45. Director of Operations
46. Director of Operations (USAF)
47. Director of Operations; Duty Officer (usually attached to a functional duty identifier)
48. DIRECTOR OF OPS
49. Director Officer
50. Director Order
51. Directorate of Operations (US CIA)
52. Directors Ohio
53. Disbursement Order
54. Disbursing Officer
55. Disbursing Officers
56. Disbursing Offices
57. Disbursing Order
58. Disciplined Oscillator
59. Discrete Output
60. Disorder    
61. Dispatch Order
62. Dispensing Optician
63. Dissolved Oxygen
64. Disto-Occlusal (dentistry)
65. Distortion Offset
66. distraction osteogenesis
67. Distributed Object
68. Distributed Operations
69. District Office
70. District Officer
71. District Overseer (Jehovah's Witnesses)
72. Ditto
73. Division OD-1
74. Division Officer
75. Division Operator
76. Divisional Officer
77. DJ04 Obock
78. Doctor of Obstetrics
79. Doctor of Osteopathic Medicine
80. Doctor of Osteopathy
81. Doctor of Otolaryngology
82. Dominica
83. Dominican Republic
84. Dommages Ouvrage (French: Work Damage)
85. Donk Out (poker)
86. Dornier (German aircraft manufacturer)
87. Drawing Office
88. Drift Orbit
89. Driver Only (train operated by the driver only)
90. Dual Operator
91. Due Out
92. Duty Officer