If I understand your question correctly, I don't think so. The icons on the left at the beginning of each topic description indicate whether you have replied to,read etc the topic but I don't think you can actively mark things.
... I will be transferring all videos from DropBox to the site where the SLs are stored. The training page will be updated as the transfers are taking place.
Sorry, it turns out I can't do this because my hosting site won't allow file sizes over 10Mb. I can count on one hand the number of videos that are that small! alf007 were you able to d/l and watch the videos? All broken DropBox links have been corrected AFAIK.