It's one of those mistakes from the Photo Lab Index that was perpetuated by countless other US publications. There were a series of articles in the BJP in the late 1950's early 60's that essentially chart the the evolution of Autophen from an early simpler PQ version of D76, the buffering was varied a few times before the final product. The articles were about things like testing effects of bromides, and the exhaustion so that they could design far better replenishment systems.
Originally Posted by Gerald C Koch
Microphen must have come from the same research but Ilford claimed that it was an entirely new developer, rather than a simple PQ version of an MQ developer. ID-68 is inter changeable with Microphen.
Microphen was sold in powder form with a replenisher, and in a wide range of sizes (mixed capacity), Autophen was available in larger sizes as a powder or as a liquid developer. Both were available in the same mid sized powder sizes. The recommended developing times were different and Microphen was stated to give an increase on the box speed.