ITU Prefix - Unallocated and Unavailable Call Sign Prefixes

Unallocated and Unavailable Call Sign Prefixes

Unallocated: The following call sign prefixes are available for future allocation by the ITU. (x represents any letter; n represents any digit from 2–9.)

• E6, E8, E9, H5, J9, On, S4, T9*, Un, V9, Xn, YZ*, Z4–Z9, 4N*.

(* Indicates a prefix that has recently been returned to the ITU.)

Unavailable: Under present ITU guidelines the following call sign prefixes shall not be allocated . They are sometimes used unofficially - such as amateur radio operators operating in a disputed territory or in a nation state that has no official prefix (e.g. S0 in Western Sahara or station 1A0 at Knights of Malta headquarters in Rome). (x represents any letter; n represents any digit from 2–9.)

• nn, x0, x1, 0x, 1x, Qx.

• no prefixes beginning with Q are used—they may be confused with Q codes.

• no prefixes with the digits 1 or 0 are used—they may be confused with the letters I or O.

• two digit prefixes (nn) are not as yet considered by the ITU.