Q: How do I insert line breaks into a multi-line text box using rules?
First off, let’s introduce the concept of a multi-line text box properly. This functionality was added in InfoPath 2003 SP1. To enable it, insert a Text Box control, then on the Display tab, check “Paragraph breaks”. I usually also set the scrolling property to “Show scrollbars when necessary” and turn on “wrap text” which maps to the usual behavior for a multi-line text box. I also usually make the control bigger..