Campaign Module Field: "Tracker Redirect URL" "Tracker" and others

Hi there,
Just ran into these four fields in the Campaign module (via Studio), NOT in the submodule “Tracker-URLs”, but in the Campaign module itself.

  • Tracker Redirect URL (refer_url)
  • Tracker Link Text (tracker_text)
  • Tracker Count: (tracker_count)
  • Tracker: (tracker_key)

What are these fields for? How could they be used? They seem to be the same as in the submodule “Tracker-URLs”, but are they of any use here?

The fourth field “Tracker” is somehow dynamically generated, though I haven’t figured out what the number means that is shown here. My first test shows “56” here, what does this mean? (Is it the Answer to the Ultimate Question of Life, the Universe, and Everything???)

Any experience / knowledge appreciated!