Just FYI, to add further to the confusion there is such a thing as a positive developer or a direct positive developer.
There are Reversal F and reversal P materials which were once sold by Kodak among others. They used either an incorporated chemical or a developer that contained a reversing agent. The developers with the reversing agent were positive developers.
In addition, some monobaths used with a donor and reciever used what is called a positive developer, as the result was a direct positive image similar to that produced by Polaroid.
So, there is a lot of confusion out there about this type of nomenclature in English.
PE