I have a vague recollection of a web service back in 2012 or 2013 that allowed you to receive and send bitoccins without any userID or password.  Instead, they just used a long randomly generated URL. As long as you knew the URl, you had access to the bitcoins, but if you didn't know the URL, then it was effectively impossible to guess and get access to anyone else's bitcoins. Perhaps what is written down is the portion of the URL that you would need to know to access the bitcoins?

Unfortunately:

• 1. I don't remember the name of the service (perhaps another old-timer here might?).
• 2. I may be mistaken, and my memory of such things from so long ago might not be entirely accurate.
• 3. If my memory IS accurate, then I think the creator of the service eventually shut it down and disappeared with everyone's bitcoins.