There has been a good deal of discussion of the issue of "cluttering" of the trade mark register, but not much solid research. However, t

'This report explores the problem of "cluttering" of trade mark registers. The report consists of two parts: the first presents a conceptual discussion of "cluttering" of trade mark registers. The second part provides an exploratory empirical analysis of trade mark applications at the UK Intellectual Property Office (IPO) and the European trade mark office (OHIM). This part contains results of a descriptive and an econometric analysis. According to our definition, cluttering arises where firms hold trade marks that are overly broad or unused raising search costs for later applicants. The report distinguishes between three mechanisms that can lead to cluttering. It also considers a series of mechanisms that work against cluttering. This discussion is based on a review of the previous literature'.