This was more to figure out the proper way to do this in order for tracking for the badge, etc on the G.M. platform.  It makes sense that it needs to originate in a challenge (and than you to Olga for pointing that out).

I don't think that just having a form on the D.C. to invite a friend necessarily makes sense, as anyone can just shoot a friend an email with the link.  If others would like to see this as a new feature I won't object though.

@Julian Matthews  - it is never too late :)  Since you know the exact version that you were upgrading from / to, I think you're in the best position to still report this as a bug to the WRC.  They can then test to see if it's still an issue on the latest versions and they can log an internal bug if that is that case.  I would encourage you to still take a little time and ensure it is officially logged.

This sounds like a classic example of leveraging embedded Python in IRIS to make use of the very large volume of python libraries that do just about anything :)  Here is an article that I found on a quick Google search on how to do this in Python:

You could just leverage the Python capabilities of InterSystems IRIS to make use of how this problem has been solved in Python!