Χωρίς να έχω ειδική γνώση του αντικειμένου, νομίζω ότι είναι "νομική συμβουλή (του δικηγόρου) για το βάσιμο της άσκησης έφεσης".
Σύμφωνα με αυτό:
Every prisoner who has protested his innocence at trial is entitled to a document written by his barrister immediately (days) after conviction. This is called “Advice on Appeal” and should encompass his/her opinion on whether there are grounds for appeal against sentence and conviction. If your barrister tells you that you have no grounds, you do not have to believe them. That is only their opinion. If they say it is not worth you having an “Advice on Appeal” because “there are no grounds”, you are still entitled to one on Legal Aid.
Αν υπάρχει καλύτερη νομική διατύπωση στα ελληνικά, δεν γνωρίζω.