When do I use "reader extended pdf"?

[joannc61987552]

I'm using Acrobat Standard XI to create simple forms. After I save the form, I have the option of Save as other.../Reader Extended PDF/Enable Forms Fill-in and Save in Adobe Reader. Can a use still fill in the form, save and print it if I don't select the Reader Extended option?

I've tested it on some people and usually they can fill in both versions.

[Bernd Alheit]

Reader XI and DC can save filled forms.

[George_Johnson]

You don't need to Reader-enable for Reader users to be able to fill-in and print. Versions of Reader prior to 11 won't be able to save a filled-in form unless the document is Reader-enabled.