Are the on0/os0...on99/os99 hidden fields still available for use?
I need to pass some custom data from my website to PayPal and back - I read where the option_name => option_selection pair feature was possible, is this still possible?
Also, I know I could use the custom field to pass my data but I want to experiment with the option_name => option_selection pairs first if they're still available - I can't seem to find official documentation supporting them.
