Reply #32

"Here is some general guidance on whom to salute, and when and where not to salute:

The hand salute is required on or off duty on all military installations.
A salute is rendered at 6 to 12 paces when walking or when at a standstill. However, senior officers must always be alert to salutes rendered when further away than the minimum distance.
A salute is held until the more senior officer has returned the salute or has passed.
Never hold anything in your right hand when saluting.
When attempting to pass a more senior officer, the more junior officer must approach on the left hand side of the senior officer, salute when abreast, and say, “By your leave…(Ma’am or Sir or Rank + Surname of the senior officer).” The more junior officer waits until the senior officer returns the salute and replies with “Carry on” or “Permission granted” or “Very well.”
Salutes should be accompanied with a greeting such as “Good Morning / Afternoon / Evening… (Ma’am or Sir or Rank + Surname).”
Officers of equal rank salute more or less simultaneously when greeting one another.
When seated outdoors a more junior officer should rise and salute to greet a more senior officer. "

http://ccmis.usphs.gov/ccbulletin/articles/Protocol_05_2009.aspx