I made an PDF Form (local) and add some help text in the form and some obligatory fields. However in the concerning fields I don't see any message or help text. For example the fields "datum" and so on ar obliged. but still i can save the file whitout filling it in.
The help text is in tooltips in the PDF file. You need to hover your cursor over the field in question and you will see the tooltip with the help text. As for marking fields as required, the check for if a required field is filled out occurs on data submit (after you click the Submit button). Hope this helps.
Software Quality Engineer
Adobe Systems, Inc.