EFZ (in Austria: Eingeschränktes Funkerzeugnis) and EZF (an older German variant: Erweitertes Sprechfunkzeugnis) are historical or transitional terms used to describe VFR-only radio certificates in German-speaking countries. Although still occasionally used informally or in older documents, these terms are being replaced by the standardized designations BFZ and AFZ.
Typically administered by Austro Control or local authorities
Recommendation
Pilots with an EFZ/EZF should consider upgrading to a BFZ/BZF or AFZ/AZF, especially if flying cross-border or planning to operate in controlled airspace with English-speaking ATC.