BAS = "Buried at Sea. This means that the person was accounted for and will not appear on the list of MIAs. Usually appears on the 'Tablets of the Missing and Buried at Sea'."
DOI = "Died of Injuries . Those who suffered fatal battle INJURIES, as opposed to WOUNDS, in combat or in combat areas, and died in a line-of-duty status.  Awarded Purple Heart Medal."
DNB = "Died, Non-Battle . Other line-of-duty deaths, such as from sickness, homicide, suicide or accidents outside combat areas [including training and manuever deaths]."
DOW = "Died of Wounds . Persons who were wounded and later died. Awarded Purple Heart Medal."
FOD = "Finding of Death . Those with this designation were "determined to be dead under Public Law 490." [Finding of death under Public Law 490 and it's amendments are made in the case of persons when--and only when--there is either conclusive proof that the person is dead or equally overwhelming evidence that under the circumstances the person could not have remained alive. These findings are made only after review and after a lapse of at least one year from the time of disappearance.]
KIA = "Killed in Action . An individual who was killed in action, whether at the front or by enemy action in the rear areas, or if a prisoner of war, whether by air bombardment of his prison camp or by being shot while escaping.  Awarded Purple Heart Medal."
MIA= "Missing In Action , also those known to be killed or dead but are unlocated."
POW = "Prisoner Of War. "
[Note: For FOD and MIA see http://www.dpaa.mil/ ]

LTC, Lieutenant Colonel;
CDR, Commander;
CPT, Captain;
1LT, First Lieutenant;
2LT, Second Lieutenant;
WO1, Warrant Officer 1st Class;
MSGT, Master Sergeant;
SFC, Sergeant First Class;
SSGT SSG, Sergeant;
SGT, Sergeant;
SP5, Specialist 5th Class;
SP6, Specialist 6th Class;
HN, Hospitalman;
CPL, Corporal;
LCPL, Lance Corporal;
PO3, Petty Officer 3d Class;
PFC, Private First Class, and
PVT, Private.

The Purple Heart medal ribbon can legally be authorized to only three groups of personnel: (details↗)
    First, those wounded or injured as a direct result of hostile enemy action.

    Second, those wounded or injured as a direct result of friendly fire (FF). (Broadly speaking, FF occurs only during a hostile encounter or initiative with, or in response to, an enemy when someone on your side mistakes you for the enemy.) Or when injured by your own non-projectile weapon (bayonet, sword, blunt instrument, etc.) or projectile weapons fire (bullet, explosive device, etc) while engaging, responding to or attacking an enemy.

    Third, POWs injured or wounded as a result of individually directed conflict or punishment with their captor in violation of any article of the Geneva Convention Rules of Warfare Concerning the Treatment of Prisoners of War whether or not the captor's government is a signatory to the Convention.

The Vietnam War Service Medal The Vietnam Service Medal is presented to any service member who served on temporary duty for more than 30 consecutive days, or 60 non-consecutive days, attached to or regularly serving for one, or more, days with an organization participating in or directly supporting ground (military) operations or attached to or regularly serving for one, or more, days aboard a naval vessel directly supporting military operations in the Republic of Vietnam, Thailand, Cambodia, Laos within the defined combat zone (DoD 1348 C6.6.1.1.5. revised September 1996) between the dates of 15 November 1961 and 28 March 1973, and from 29 April 1975 to 30 April 1975. The National Defense Service medal is an automatic award with the U.S. Vietnam War Service medal.