I want to keep track of the events my customers go to. These can be events that I organise, but also events organised by other companies. The events are mostly free of charge. I found the Event module, but that creates invoices of every registration. Since most of the events are free, or not even hosted by my company, I don't want to create invoices. Is there a way to keep track of the events my customers go to? Without invoicing them? Maybe putting a partner category on them with the name of the event? Or maybe creating meetings in the calendar and use those to track events instead of normal meetings? Any ideas?