The planar minimum linear arrangement problem is different from the minimum linear arrangement problem

In various research papers, such as [2], one will find the claim that the minLA is optimally solvable on outerplanar graphs, with a reference to [1]. However, the problem solved in that publication, which we refer to as the planar minimum linear arrangement problem (planar minLA), is different from the minimum linear arrangement problem (minLA), as we show in this article.