Some time ago I bought Adox CMS 20 + adotech developer from the now sadly missed J&C. Later on I bought some Adox Ortho 25, as I was running out of the old J&C ortho film in 35mm. There is a labelling confusion between the two films, and I think it's more twisted than I thought at first.
Here's the easy part: Adox CMS 20 is sold in white canisters, and because it's a microfilm-type of emulsion, it requires the special Adotech developer to give proper continuous tone results. Unexposed, the film is grey-ish, and the edge markings read "ADOX CMS 20" when developed.
Adox ORTHO 25 is sold in similar white canisters, but it is an orthochromatic emulsion that works well in pretty much any standard developer. The unexposed leader of film is reddish. Here is a picture to illustrate this (the scotch tape is just holding the canisters in place).
Both films are coated on a very tough PET base.
Here's the harder part: if you look at the label of an ORTHO 25 canister, it is very likely that you might see an "Adox CMS 20" label underneath. What's important to not is that the EDGE MARKINGS of my ORTHO 25 are labelled "CMS 20."
I have all reasons to believe that this is an error, as the look of the two films is dissimilar, as well as the color of the unexposed film is different.
What's more, by comparing a developped strip of authentic CMS 20 with another one of ORTHO 25, I can see the following differences:
* CMS 20 uses a very elegant font for frame numbers (Arial-ish). ORTHO 25 uses the less gallant Courier, giving it a more computerish look
* CMS 20 has a long string of numbers at the top of the strip, "52360204" on my film; my ORTHO 25 has the shorter "061"
* CMS 20 has Bell & Howell-like perforations while ORTHO 25 has the Kodak Standard perforations (cf.
http://en.wikipedia.org/wiki/Image:35mm_sprockets.png)