Do you want to push/pull your film, but your camera doesn't let you override the ISO value?
Did you buy cheap film with no DX encoding in the canisters?
I have the solution for you!
Some might scrape the paint to uncover the metal contacts. However, I find it very time consuming.
I prefer to make DX labels and stick them to the canisters.
More information on DX encoding:
DX encoding simulator
If you find something wrong in this instructable, please tell me.