Unlike seals, flags are commonly considered today to have a collective significance, symbolizing the unity of a country, regiment or some other group or assembly of people. But it was not always so. True enough, the Roman standard symbolized the legion and was not personal to its commander; but in mediaeval times the feudal forces were composed of knights and men-at-arms who followed the personal banner of a knight banneret or minor baron. These in turn followed the standard of their overlord or monarch. It was only in later years that military flags or Colours became attached to the Regiment rather than to its commander.
The position is indeed not quite clear today. Some years ago an official statement was made in Parliament that the Union Flag is the National Flag and may be flown on land by any British subject. But no Royal Warrant was issued to give effect to this statement, and the College of Arms has ruled that the Union Flag is a Royal Flag and that, strictly speaking, its use should be confined on land to Royal Government Property only. But, although some believe that the Union Flag remains the fighting flag of the Sovereign, most people are now content to accept the statement made in Parliament.
Colonies normally have two flags, each of which bears the Colony Badge. These flags are authorized by Colonial Regulations, which are "direction for Governors for general guidance given by the Crown through the Secretary of State for the Colonies."
The "Governor's Flag" is the Union Flag with the Colony Badge emblazoned in the centre on a white ground surrounded by a green garland. It is flown on Government House or other official residence of the Governor from sunrise to sunset when the Governor or Officer Administering the Government is in residence, and is also used by the Governor or Officer Administering the Government when absent on land from Government House, for example on his car, or when embarked in a boat or other vessel.
The "Colony Flag" is the British Blue Ensign with the Colony Badge emblazoned in the centre of the fly (i.e. in the centre of that part between the Union Flag and the end of the flag). It is worn at the stern of all vessels which belong to or are in the service of the Government of Hong Kong.
These two flags have in fact no specific names, but are usually known as the Governor's Flag and the Colony Flag, the latter being flown on occasion at international meetings and conferences.