What is a Referred MarkWatch
More about University of Greenwich
"Referral means you have been given the opportunity to undertake further assessment to try and retrieve the credit from any modules you have failed. The final module mark will be capped at the pass mark of 40%, which means that even if you achieve a result higher than this, your final module mark will still show as 40 on your transcript."
Hopefully that makes sense in your context.
For example, if you fail an exam and resit it, the grade is capped. That would mean that even if you get 60/100 correct on the page, you would only be able to get a 40% on your final transcript. That is, unless you submit an extenuating circumstances form if you were in hospital etc, which may cause people to miss exams or to not do as well as they can.
I hope this clears things up a bit!