indicate, designate

Question 1

General Rules for designators

Answer 1

The same designator will not be registered for more than one AOA, aeronautical authority or service.
No more than one three letter or telephony designator will be registered for each AOA, aeronautical authority or service.
When a designator is no longer required, ICAO should be informed immediately. Any such designator so released will not be reassigned until a period of at least 60 days has elapsed.

Question 2

Who assigns location indicators

Answer 2

Location indicators are assigned by states and are checked by ICAO for conformity with the formulation and assignment of location indicators set out below.

Question 3

formulation and assignment of location indicators

Answer 3

The boundaries of these areas need not necessarily coincide with the boundaries of an state, territory, or FIR but are decided soleyl from a consideration of the requirements of the AFS so as to assist message traffic routing processes to the maximum possible extent
2) Each seperate state or territory is assigned a seperate identifying letter to permit diffrentiation between that state or territory and other states or territories in the same AFS routing aRea.

Question 4

Where are seperate identifying letters assigned?

Answer 4

Seperate Identifying letters are assigned to parts of a state or territory where:
a) a seperate state or territory is itself assigned an AFS routing area
b) routing uncertainties can exist at stations feeding traffic into that State or Territory
c) by doing so these routing uncertainties can be removed or alleviated.

Question 5

a seprate state only contains tributary stations

Answer 5

No seperate identifying letter is assigned where a seperate State or territory contains only tributary stations

Question 6

Assignment of location indicators

Answer 6

The first letter shall be the letter assigned to the AFS routing area within which the location is located.
The second letter shall be the letter assigned to the state or territory within which the station is located
The third letter shall be so assigned as to assist in the process of routing that communication center.
The fourth letter shall be assigned as the states desire,, except for exeptions

Question 7

Adresses of centers in charge of FIR

Answer 7

Such an adress indicator consists of the location of the ATS center in charge plus one of the following four letter designators;
ZQZX if the message is related to IFR flight
ZFZX if the message is related to a VFR flight