This TR is an extension to CEN/TR 15855:2009. This original report on Barriers to Trade, prepared in response to Mandate M/366 given to CEN/TC 351 by the European Commission, identified that some of these barriers were truly technical or legal barriers to trade which can usually be overcome or minimised by technical harmonisation work, but others were quite legally in place, sometimes voluntary, but were nonetheless still seen as a barrier to the use of certain products in a free market place. This report is an examination of these concepts in more detail and an attempt to identify the reasons behind the presence of barriers to use and to present specific examples in more detail.