A couple of extra points
The Royal Air Force Ensign is the flag flown at all working RAF stations and formations. It is described as "on a field sky blue, a Union Flag in the upper hoist, the field charged with a Royal Air Force roundel". It is accorded the same dignity as the national flag, and the two are rarely flown together except at joint Army/Air Force formations. It is permitted to drape the Ensign over aircraft under specific circumstances, but it is forbidden to use the Engsign for decoration or to drape caskets of deceased servicemen. In this respect, there are strict rules in the Queen's Regulations for the Royal Air Force, laying out exactly where the Ensign may be used. On working stations it is usually raised at 0730hrs throughout the year, and lowered at 1630 (winter) or 1800 (summer). When it is raised or lowered, the Orderly Sergeant plays a single blast of the whistle, all personnel stop and face the Engsign, and all officers salute. When it has been lowered or raised, the Orderly Sergeant plays two blasts of the whistle, and all personnel return to normal duties.
The White Ensign is the flag of the Royal Navy, and, again, very strict rules in the Queen's Regulations for the Royal Navy set out exactly where it can and cannot be used/flown. When it is raised a bugler will play Reveille, and all personnel face the ensign pole (officers salute). When it is lowered, the bugler plays Sunset, all personnel doing the same as for raising. In either case, when it has been raised or lowered the bugler plays two notes to signify the end of the ceremony.
Half-masting, certainly in the UK, is performed in a specific manner.
- If the flag is not flying, when it is flown at half-mast it is to be raised fully, then lowered slowly to 2/3 the length of the flag pole. During the ceremony, all spectators are to stand and salute or uncover (remove hats) as appropriate.
- If the flag is already flying, it is first lowered fully, then the above actions are performed. Throughout the ceremony, spectators are to stand and salute or uncover.
- When the flag is lowered from half-mast, it is first raised to the top of the flag pole, then lowered slowly in the usual manner.
- To raise the flag fully from half-mast, it is first lowered at at 3, then raised normally to full-mast. It is usual for individuals to remove black armbands following this procedure (if applicable).
When flown on Army Units the Union Flag is treated in the same way as the RAF Ensign. The Union Flag is NOT to be called the "Union Jack" unless it is flown from a ship or vehicle.