A customer wanted a complete list of all notifications balloon tips in Windows.
There is no such list. Each component is responsible for its own balloon tips and is not required to submit their list of balloon tips to any central authority for cataloging. In order to create such a list, somebody would have to go contact every component team and ask them for a list of all their balloon tips, and that component team would probably undertake a search of their code base looking for balloon tips. And figuring out the text of each balloon tip can be tricky since the text may be built dynamically. (And the customer didn't ask for an explanation of the conditions under which each balloon tip may appear, but that's probably going to be their follow-up question.)
It's like publishing instructions on how to display a message on the message board, and then somebody asking the message board manufacturer, "Please send me a list of all messages that might appear on the message board." The message board manufacturer doesn't know how its customers are using the message board. They would have to go survey their customers and ask each one to build an inventory of every message that could potentially be shown.
In other words, this customer was asking for a research project to be spun up to answer their question.
It turns out that they didn't even want this list of balloon tips. They just had a couple of balloon tips they were interested in, and they wanted to know if there were settings to disable them.
But even though that was their stated goal, they still reiterated their request for a list of balloon tips. The customer liaison asked, "Is there a possibility is getting a list of balloon tips generated by Windows itself? Even a partial list would be helpful. Can we help with this?"
What the customer liaison can do is contact each Windows component team and ask them, "Can you give me a list of the balloon tips your component generates? Even a partial list would be helpful." I wished him luck.
The customer liaison replied, "I passed this information to the customer and will follow up if they have any further questions." No follow-up ever appeared.