Here you go, public promise article in Polish wikipedia. It seems there is no english translation - go figure. It is a part of the European legal system, and p

Here you go, public promise article in Polish wikipedia. It seems there is no english translation - go figure. It is a part of the European legal system, and provisions for it appear in German, Italian, Polish, Turkish and French laws. It's a one-sided contract essentially, so there is no need for a member of public to sign it. But if you don't fulfill it, the affected member of public can sue you. https://pl.wikipedia.org/wiki/Przyrzeczenie_publiczne https://pl.wikipedia.org/wiki/Przyrzeczenie_publiczne