The salute dates from medieval times, when knights showed their friendly intention by raising their weapon hand, empty, and opening the visor of their helmet.
When you salute officers, you acknowledge that they hold their rank by virtue of a commission from Her Majesty the Queen. That's why they are called "commissioned officers". You must understand that saluting is not an act of servility. In medieval times, serfs used to turn their eyes to the ground when passing "betters", but as citizens in a democracy we look our superiors in the eye when we salute because while we may differ in rank, we are all equal before the law.
The trust, loyalty, and respect on which good discipline is built must be mutual, not just one-sided. In civilian life when someone says "Thank You", we return the courtesy by replying "You're Welcome". Similarly when you show your trust, loyalty, and respect for an officer by saluting, the officer "returns" the salute to show his trust, loyalty, and respect for you. It is discourteous not to return a salute.
Sailors ("tars") developed the practice of saluting with the palm of the hand facing downward, because the tarred ropes on board ship made their hands dirty. Since the unification of the Canadian Forces in 1968, we all salute as the "senior service" does.
b. If you are standing still and an officer passes you, come to attention and salute. If you are on the move and you pass an officer, turn your head in his direction and salute. But keep marching; you don't have to halt to salute. If is always courteous to add a greeting, such as "Good evening, sir."
c. In Commonwealth forces (unlike American forces) if you are not in uniform, or if you are in uniform but do not have your beret on, you do not salute - just come to attention or turn your head as the situation requires, and add a polite greeting. If you are wearing a civilian hat, doff (lift) it or touch the brim courteously; but don't turn this gesture into a drill movement.
d. In a "formed" group (when you are formed up in ranks) come to attention when you are spoken to, but do not salute when in ranks. When a formed group has to pay compliments, the person in charge will call the group to attention and salute. The person in charge of marching group will salute when passing a junior officer, and will order an Eyes Right or Eyes Left when passing a senior or general officer.
e. In an "unformed" group (when a bunch of you are standing about or walking informally) all members of the group salute an officer. If you pass a group of officers, or a group of officers passes you, only the most senior officer will return the salute.
f. If you are seated or busy about some task when an officer approaches, stand up and come to attention. When a seated group is called to attention (usually with the order "Room") as in a classroom, members sit facing front with their feet together and their arms to their side. When this would be awkward or unsafe, members are ordered to "Stand Fast"; they stop whatever activity can be stopped safely, until they are ordered to "Carry On".
g. When you work closely with junior officers, you can avoid "bugging" them by saluting only at the beginning and end of the day, and on the parade. This must not lead to any slackness about saluting. Salute senior and general officers at all times.
h. One does not normally salute in a building except when entering and leaving an office, or interrupting his classroom. But for training purposes, salute inside an armoury as you would outdoors.
j. Salute members of the Royal Family, the Governor General and Lieutenants Governors, and vehicles bearing their personal flags.
k. Salute when you see a vehicle displaying a general officer's plates (silver maple leaves on red) or a base commander's pennant. the person is inside, even if you cannot see him.
m. Face the music and saluting during the playing of the Royal Anthem, the National Anthem, the Last Post, and Reveille.
n. Salute when the National Flag is raised or lowered, or passes by in a parade, but not when you walk past a flag on a flagpole - not even in front of camp headquarters.
p. Salute when artillery guns, uncased regimental colours or the Royal Canadian Army Cadet flag pass by in a parade.
q. Salute when you pass a cenotaph or war memorial.
r. When you board or leave any of Her Majesty's ships, face the quarter-deck (aft) and salute. This ancient custom has a religious origin. Sailing ships used to display a crucifix on the quarter-deck, and devout sailors used to cross themselves as a prayer of request, or thanksgiving, for a safe journey.
s. Pay similar respect to the Head of State, commissioned officers, flags, anthems, and ships, of all Commonwealth and other friendly nations.
t. Stand still and salute the coffin or hearse in any civilian or military funeral procession. If you attend a funeral in uniform, you may pay your last respects by saluting at the graveside.
u. As a mark of respect, you should also salute an officer's spouse, any civilian from whom you receive a presentation on parade, and any civilian to whom you wish to show respect.
v. If you have to salute when you are carrying a rifle, adopt the position of Shoulder Arms, then bend your left elbow and strike the sling with the palm of your left hand, finger open and pointing to the right. You may do this at the halt or on the march. An armed guard at the halt presents arms to senior and general officers.
w. Stand to attention when an armed guard marches by.