Which features of charters did Jean Mabillon examine in De Re Diplomatica?

In his foundational work De Re Diplomatica, Jean Mabillon established a comprehensive methodology for the critical study of documents, specifically to distinguish between genuine and false charters.123

To determine the authenticity and dating of these manuscripts, Mabillon conducted a detailed examination of both external and internal features, including:

• Physical materials: He analyzed the ink and parchment used in the documents.3
• Handwriting: He pioneered the study of paleography, examining the specific styles of script to verify their historical context.23
• Comparative analysis: He systematically compared individual charters against others to identify inconsistencies or patterns indicative of forgery.3

By applying these rigorous standards of evidence, Mabillon transformed the study of old documents into a reputable science, effectively founding the field of diplomatics.123