Regarding this subject, the HAEU preserves notarised deeds and private contracts sealed with the seal of the relevant private entity, as legal documents produced by non-state actors (foundations, organisations, legal persons). In such cases, the seal plays a role comparable to that observed in official instruments, as an emblem of sovereignty, manifesting political and legal authority and contributing to a staging of power. It inscribes the instrument within a shared diplomatic space, expressing a legal capacity. Its primary function is to authenticate the document, identify the issuing entity, and guarantee its validity and enforceability. It may be the seal of a private institution, a notary, or a legal person. We deal then with a seal of legal legitimation that keeps a strong visual dimension.

It is quite remarkable that the common point shared by all these findings is their origin in Northern European Protestant monarchies. In the mentalities of these countries, still imbued with a sense of sovereign solemnity, the use of the seal had not yet become entirely obsolete. Without preventing a more material reliance on the exclusive use of the signature, the seal remains here a witness to a past exoticism, whose symbolic meaning was already beginning to fade from collective memory.