It would be great to have a warning when creating/editing a connection and selecting "Use an existing credential" in a shared document ;-)
My coworkers are often mistaken when they create a new connection that use a credential stored in there own Application document and intended to be shared (meaning to use with the "Specify a credential name") !
It leads to a connections asking for a valid credential as it, when you edit the connection, display a "[No credential assigned]".
I think that a lot of new users are not aware of the real difference between both options if they're not used to use a shared document !
That's a great suggestion, thank you Nicolas!
I will see how we can make this clearer in the UI.