Produced in order to be prepared in case of a military attack from Eastern Europe.
Assuming that in case of a successful invasion the enemy would take possession of the Deutsche Mark notes, all regular DM-notes would have been declared immediately as no longer valid.
"Bundeskassenscheine" were to be circulated instead, - in order to supply the population with sufficient cash for their daily basic needs. Bundeskassenscheine would have been of course not redeemable on an international level.

The existence of Bundeskassenscheine was kept secret and was not known to the public, until a few examples were stolen and offered to collectors.