geting fields values of a related item

Maybe I didn't explain myself correctly.
What I did, and it works, is:
In the field definition, under the HTML attribute I put the following:
{"text":"{{text}}", "subtitle":"{{sub_title}}", "short":"{{short_desc}}"}
and it works. I have to do somting in my retrieving code before decode it to JSON with the newline BUT that manipulation is easy.

For the item data retrieving - I saw the FAQ you mention BUT could not understand from a print_r($item) of the specific item what its original ID