If you have upgraded from Adobe Reader 7 to a later version and your forms contain read-only fields, you may have noticed that you can now tab into those fields in Reader 8+. This was not possible in Reader 7 and earlier.
As a workaround, change the access property value for the fields you want to remove from the tabbing order from “readOnly” to “protected” in your XDP forms. Fields marked as “protected” do not participate in the tabbing order.
Alternately, write a script to change the access property from “readOnly” to “protected” in your XDP XML source code.
The tabbing feature has been documented for read-only fields since Designer 7.1 but has only been enforced in Acrobat/Reader since version 8. The necessity for tabbing into read-only fields comes from the Accessibility standards. Screen readers must be able to read the read only fields on the page, and screen readers work off the tabbing order.
This is the correct behaviour for read-only fields.
The “protected” option is not available in Designer 7.1 but is available in later versions. If you require this option in Designer 7.1, contact Adobe support to request a patch for Designer (you need a valid M&S contract to request this patch).