Which medieval documents were considered public documents?

In the field of diplomatics, medieval documents are broadly classified into two categories: public and private. Public documents are defined as those issued by emperors, kings, and popes.1

These documents were typically produced by a chancery—an office of public records or archives—which served as the working establishment for the sovereign's principal advisor, the chancellor. Within this classification, royal documents were often categorized as either diplomas or mandates, while papal documents were generally classified as letters or privileges.21

These public records were essential for a strong, centralized government, as they provided formal evidence of legal transactions, grants of rights, or administrative commands.21