The 2014 conference proceedings are now published and available on the ICOS 2014 website:
Names and Their Environment. Proceedings of the 25th International Congress of Onomastic Sciences, Glasgow, 15-19 August 2014. 5 vols, edited by Carole Hough and Daria Izdebska. Glasgow: University of Glasgow, 2016.
The proceedings are available for download either by volume (five volumes in total) or by individual paper (organized by thematic section on the website).