The paper "On the solution of differential-algebraic equations through gradient flow embedding," Computers and Chemical Engineering, 103 (2017), 165-173, presents an algorithm that is designed to integrate some index one DAEs. This letter reviews index one DAEs, and clarifies how the assumptions of the algorithm fit within a more general framework. The types of index one DAEs for which the new algorithm are not appropriate are discussed. (C) 2017 Elsevier Ltd. All rights reserved.