Following the decision of the International Radio Telegraph Convention signed in Washington on 25 November 1927
Effective from 1 January 1929 (Resolution 436 of ICAN/CINA)
|United States of America||K, N or W|
|British Empire||G or M|
|Chile||CA to CE|
|Canada||CF to CK|
|Portugal||CS to CU|
|Belgium||ON to OT|
|Denmark||OU to OZ|
|Sweden||SA to SM|
|Poland||SP to SR|
|Greece||SV, SX, SY or SZ|
|Kingdom of Serbs, Croats and Slovenes||UN|
|Canada||VA to VG|
|Australia||VH to VM|
|British Colonies & Protectorates||VP to VS|
|Free City of Danzig||YM|
|New Zealand||ZK to ZM|
|South Africa||ZS to ZU|
The nationality and registration marks borne by aircraft shall be constituted by a group of five letters.
The nationality of the aircraft shall be indicated by the first letter or the first two letters of such group.
A hyphen of a length equal to the width of one of the letters shall be placed immediately after the nationality letter or letters.