When merging Multi-line fields from SharePoint into a template it might merge the content in with HTML elements encapsulating it.
Example of the merged result:
To get around this, do the following in the template:
1. Click on data tags.
2. Click on the data source.
3. Click on add tag in the bottom of the right side pane.
4. Click on Calculated tags.
5. In the text box of the calculated tag type; <HTML>
6. Click on select tag and select the multi-line field.
7. Then type in the closing html element; </HTML>
8. Click on OK to add it to the data source.
Now, instead of using the original multi-line tag, the calculated field will now need to be used in order to remove those HTML elements.
It should now merge like this:
For more information around calculated fields and data source modification, click here