There are six distribution statements, and each one is designated with a letter:
Distribution Statement A
Distribution Statement B
Distribution Statement C
Distribution Statement D
Distribution Statement E
Distribution Statement F (USE PROHIBITED EXCEPT UNDER RARE CIRCUMSTANCES)
The boxes in column two of this page will explain each one in brief.
Another term for controlling office is releasing authority.
Distribution A
Approved for public release: Distribution unlimited.
Note: Everybody in the world can see Distribution A.
Distribution B
Distribution authorized to U.S. Government Agencies (reason) (date of determination). Other requests for this document shall be referred to (controlling DoD office).
Note: Everyone within the federal government can see Distribution B (IRS, EPA, DoD, etc.)
Distribution C
Distribution authorized to U.S. Government Agencies and their contractors (reason)(date of determination). Other requests for this document shall be referred to (controlling DoD office).
Note: Distribution C adds "their contractors" to the list of U.S. Government Agencies authorized by Distribution B.
Distribution D
Distribution authorized to Department of Defense and U.S. DoD contractors only (reason)(date of determination). Other requests for this document shall be referred to (controlling DoD office).
Note: Distribution D subtracts all "U.S. Government Agencies" (approved previously by Distribution C) and limits the distribution to DoD and U.S. DoD contractors.
Distribution E
Distribution authorized to DoD components only (reason)(date of determination). Other requests for this document shall be referred to (controlling DoD office).
As of April 28, 2016 there are new policies in place for the use of Distribution F. DoD Instruction 5230.24, "Distribution Statements on Technical Documents" now prohibits the use of Distribution F on classified or unclassified scientific and technical documents. However, distribution statement F may be used under rare and exceptional circumstances when specific authority exists, or when need-to-know has been verified.
If you are authorized to use distribution statement F under an exceptional or rare circumstance, then see the Distribution Statement F box directly below this one.
Distribution F
Further dissemination only as directed by (controlling office) (date of determination) or higher DoD authority.
Every technical document (GRP, thesis, dissertation, etc.) published by AFIT through DTIC must include one of these six distribution statements in accordance with the AFIT Style Guide and DoD instructions. The fourteen reasons can be examined in brief by clicking the eponymous tab above.