The AMT executive editors received a complaint that the method presented in the paper by Mak et al. (2013) was largely based on an earlier invention by Pieter Tans (see e.g., the paper by Karion et al., 2010), but this earlier invention was not mentioned or referenced in the paper by Mak et al. (2013). For the AMT executive editors it is not possible to make a clear decision in this conflict. Unfortunately, it was also not possible to reach a consensus between the involved parties. This editorial note thus has two aims: 1. to make the readers of the paper by Mak et al. (2013) aware of this conflict;