Filling forms with Reader

Hi,

I'm testing a PDF-form-based process and would like to ensure I have everything covered. I want to make absolutely sure all my users will be able to fill in forms and save filled forms. I have two questions:

1. Has Adobe issued any sort of documentation detailing under what conditions a PDF form can be filled and saved with Reader (e.g. software versions, specific features in the form...);
2. I realized that all PC's on which I tested the filling and saving of forms in Reader also have Acrobat Standard or Pro. Is there any chance that the test succeeded because of the availability of some Acrobat library, but wouldn't have if the PC only had Reader installed?

Thanks!

R.