Here’s a BBC article about the military custom of saluting:
http://www.bbc.co.uk/news/blogs-magazine-monitor-30679406
The chart mentioned in the story…
…has some suprisingly amusing cartoons for an official government publication dealing with a serious topic like military ranks. Then again, I once heard a rule of thumb on shipboard behaviour supposedly given to enlisted sailors: “If you see something, salute it. If it doesn’t salute back, pick it up. If it can’t be picked up, paint it.”