In November 2015, members of the Eurovent Product Group ‘Air Filters’ published an updated version of Eurovent Recommendation 4/19, offering public institutions a ready-to-use manual for writing a valid requisition, public tender, or enquiry. The most important changes compared to the version of 2012 constitute an update of references and wordings, and removal of classes that are now being dealt within the Operation Manual of the Eurovent Certita Certification performance certification programme for air filters. According to Mr Jan Andersson, Chairman of the Eurovent Product Group ‘Air Filters’, the ‘right combination of an efficient particulate air filter, IAQ requirements and low energy consumption puts the focus on the correct specification and validation of air filters’. The updated Eurovent document provides for ‘hands-on recommendations and guidance for authors public enquiries covering air filters’. This is the English version of the document.