Prepopulate: Custom html

Is it possible to take a textbox that has a list of items separated by the return key and I would like the jotform to be prepopulated in the same format? Right now when I prepopulate my form it is one giant text but I would like each item to be separated and have their own line so it's easier to read the list.

Unfortunately that isn't possible in Jotform. You would have to download the full source and add your own code. Then you would have to host your form on your own web server.

To prepopulate please read this guide:

Prepopulating-Fields-to-Your-JotForm-via-URL-Parameters 

Or you can try the prepopulate app:

http://prepopulate.jotform.io/