Reading an Official Seal or Stamp as Evidence
Launch library · evergreen read

A seal or stamp signals that a document passed through a specific institutional process, which lends it a particular kind of authority, though that authority applies to the process the seal certifies rather than automatically extending to the accuracy of every specific claim contained within the stamped document.
Different institutions used different seals across different periods, and changes in a seal's design over time can themselves help date a document, or reveal that a document has passed between different offices or authorities over the course of its working life, quietly recording a bureaucratic journey that the document's own text may never directly mention.
Treating a seal as evidence of process rather than evidence of content keeps a writer from overstating what the stamp actually proves, while still recognising it as a genuinely useful clue toward the document's institutional path and rough date of creation across the whole of its working life.