The utility of internal conversion is largely untapped as of yet, due to the difficulties associated with modelling it. However, it has already been proven an effective suite of control in numerous applications. What researchers need to do is continue their work! There is so much more than can be done, and while arduous, the results will be well worth it. To aid in this desire, it is our hope this review will aid those in chemical physics to better choose an appropriate model, resulting in a deeper insight into the science, and that this work inspires others to continue to push the boundaries of what is possible...