Did a little search for you on the net so take the qoute for what it is, this is what one person had to say.

[font=verdana]Process EM-25 was the final process for non-prehardened movie
films, and an interim process, just before EM-26 came out. It was only
made for a short time period, and it more similar to the E-6 process
colorwise, but the film still had to be run thru Pre-Hardner and then
Neutralizer and a rinse, prior to being in development.[/font]
Rocky Mountain Film processes old film and has an explaination of EM-25