You're taking a very big risk there. Preview might allow you to do that, but it will also corrupt your form in various ways. It's very likely that if you submit such a form to the IRS it will be rejected out of hand.

You posted your question in the Acrobat JavaScript forum. I moved it for you to the Adobe Campaign Classic forum.

Try asking here: LiveCycle Designer

Find an old copy of Acrobat Pro that has LCD bundled with it is the only option, I believe.

Yes, it would have been, actually. The LCD forms are completely different to the normal PDF files and you can't use the same "engine" to generate both of them. I do believe that they should not have been called PDF files, though, as they are not really that at all.

Just don't try to submit it digitally, as it will probably get rejected...

I moved your question to the LiveCycle Designer forum.

Is this an LCD form?

LCD = LiveCycle Designer

LiveCycle Designer