Button Widget Annotations provide user interactivity on a page of a PDF document. There are three types of buttons available: push button, radio button, and checkbox. Depending on the type of button there are different values that may be defined:
The button’s caption. Available only for push buttons. This is the text displayed in the button.
The field name. Available to all button styles.
The on state text. This is the string that is associated with
the on state of a radio button or checkbox control. This text is not
shown to the user, but is important when retrieving information on
submitted forms. The off state text is always
For check boxes, to have the buttons behave independently they each need a unique field name.
For groups of radio buttons, each individual button in the group should have the same field name as the others, but a different on state value. This is required for the group of radio buttons to work correctly as a unit.