Along with the dynamic evolution of the new field of digestive endoscopy, the need of unified and unambiguous terms for endoscopic findings arose in the second half of the 20th century. In collaboration with the OMED members, professor Zdeněk Mařatka drew up the first internationally acknowledged terminology for digestive endoscopy which was used in the full range for a period of almost 20 years. The technical progress later brought with it endoscopes which made it possible to view flat lesions, frequently overlooked until then. The classification of the surface lesions was further specified by the Paris Classification which drew from the experience of Japanese endoscopists. Thanks to the new endoscopic methods of imaging mucosa in vivo and the pit-pattern and vascular-pattern classification, we can currently estimate the biological nature of lesion with great accuracy and therefore choose the best therapeutic procedure.