issuerDisplayName

Localized issuer display name (e.g. "e-Boks"), or null when the credential carries no issuer display metadata.

Prefers the entry whose locale matches languageCode (exact, then primary subtag), then the first available. Unlike issuerName this returns null rather than a hard-coded "Unknown issuer" string, so callers (e.g. the transaction logger) can decide how to render the absence.