Read-Only QR Codes

25 formats our checker recognizes and explains, but our generator won't make. Here's why, grouped by reason.

check.qr.abundera.ai reads and explains 150+ QR and barcode formats, including the 25 below. Our generator deliberately never produces these 25, not because they're rare, but because each one only means something once a specific issuer, registry, or live secret stands behind it. A generator that made blank copies of these wouldn't be doing anyone a favor.

Every type here can still be scanned and read at check.qr.abundera.ai, our free checker. Click through to any type below for the full explanation of who issues it, what standard it follows, and why we leave it alone.

Issued by an authority or registry

The identifier is minted and assigned by an issuing authority or registry (a tax authority, health ministry, or goods-serialization registry). It can be checked, not manufactured by a third-party tool.

Signed by the issuer

The code carries a cryptographic signature from its issuer. Anyone can verify it; nobody can forge a valid one without the issuer's private key.

Carries a live secret

The code contains live secret material (2FA seeds, a vault export, a private key or bearer token). Generating one would mint or leak a real secret, so we refuse by design.

Refreshes on a timer

The code refreshes on a timer, so a static image is stale within about a minute. There is nothing fixed to generate.

Blocked for safety

The scheme can execute code or read local files. We deliberately never produce these.

Last updated: 2026-07-19.