Mitchell and Soviet Bloc leave space above and below the letters on the white band; Pannon Sun in the 2003–04 fleet supports letters touching both edges.
Sache describes a white pennant with the Hungarian national flag running its full length and a black anchor towards the hoist. It flew above the Budapest building and appeared as a logo on a blue rectangle. He tentatively likened its role to an unofficial civil ensign; this is an interpretation, not an established status. The original flag reference is numbered H578.
Mitchell dates M580 to 1970 but supplies no period for M579.
Keep the explicit scope label independent; no alias or company identity is inferred.