I understand structured mentorship refers to the type organised by a known or reputable organisation. Lecturing in a university or similar presentation is not necessarily mentorship but is listed as an example of evidence for optional criteria two, so you can use it but I won’t call it mentorship. From my experience, I would recommend you explain the nature of the mentorship programme and give a bit of context. My mentorship evidence for a U.S Government programme was not considered, I had to raise it in my review. Don’t assume they know the organisation you are referencing in your application, give some background information.