High-resolution scans prevent further aging of the 1940s–1990s newsprint.
| Indicator | Safe PDF | Suspicious “UPD” PDF | |-----------|----------|----------------------| | Metadata author | “Sonnenfreunde Verlag” | “User” or blank | | Creation date | Matches issue date | Future or modified date | | Embedded fonts | Standard | Minimal (to hide edits) | | Digital signature | Present (Adobe CDS) | None or invalid | | File size | ~8-12 MB | Under 2 MB (text-only recreation) |
: For researchers looking for a comprehensive list of specific issues and years (dating back to 1950), the Sonnenfreunde Catalog on LastDodo provides a detailed record of at least 93 different items, though it is a catalog for tracking collections rather than a direct download site. Overview of Issues