A question about a plaque

[hibacusa]

Hello everybody. This plaque comes from a private collection from Leros island, in the Aegean sea in Greece. Does anybody knows whats is it about and for what the letters stand for? Thank you in advance for the replies.
Regards,
Nikos.

[gianni59]

Ciao.
Codice Internazionale Nautico:
https://it.wikipedia.org/wiki/Codice...ionale_nautico
Giovanni

[hibacusa]

Hello Giovanni. Thank you for taking the time to reply. That's very helpful. But let me ask you. At the link you've sent me the flags for letters N,A,O are different than the ones shown on this plaquet. Can you tell me why?

[gianni59]

Hello. In my opinion the blue of the N and A has faded.

[ziomanno]

It is highly probable that this plaque indicates the flag coded name of a Royal Navy ship or of a coastal military (Navy) radio station.
Nowadays every ship has a similar coded name, composed by the letter indicating the Country (i.e.: I for Italy), followed by 3 letters. If so, this plaque once was probably applied in a Regia Marina ship's bridge.

[hibacusa]

Hello Ziomanno. Thank you for finding the time to reply. Your info are very helpful, as it is not my field of knowledge. Regards, Nikos