Name stamps, printed backstamps, and what they can and can't prove.
Marks appear across pottery history: Roman potters stamped samian bases and mortaria flanges; stoneware makers impressed medallions; and from the 18th century printed or impressed factory backstamps become standard on refined tablewares, often with pattern names and even registration codes that date designs precisely.
Registration marks and numbers are gold: British diamond registration marks encode an exact date range (1842–1883), and 'Rd No' series run onward from 1884. The words 'England' (from 1891) and 'Made in England' (20th century) are quick period fences for export ware.
Copy the mark exactly — spelling, punctuation, device — and photograph it square. A mark dates manufacture, not deposition: a Victorian plate sherd can reach a field a century after firing. And remember famous marks (Meissen crossed swords, Chinese reign marks) are the most imitated of all.
Identifying pottery and ceramics
Identifying terracotta figurines