Honorary membership diplomas were presented during the ceremonial opening of the 51st Congress of the Society to the following individuals:
- Professor Eugeniusz Czecior
- Professor Magdalena Józefowicz-Korczyńska
- Professor Małgorzata Wierzbicka
- Professor Andrew Fishman (USA/Serbia)
- Professor Martin Jurlina (Croatia)
- Professor Cem Meco (Turkey)