From ACT Wiki
A loan instrument usually governed by German law.
Schuldschein is sometimes translated as 'certificate of indebtedness'.
Schuldscheine are bilateral loans, privately placed, unlisted and unregistered.
They are not securities as the debt is legally constituted by the underlying loan agreement, rather than by the certificate of indebtedness itself.
Historically the largest category of Schuldschein issuers has been German public authorities, but the market is also tapped by corporate borrowers and financial institutions.
Also known as Schuldscheindarlehen (SSD).