give it the name vanguard USD or Vanguard shrt income or Vanguard whatever you want.. I don’t know if this is new…. but go ahead and try it.
Also, I see the developers have had nothing to do the last week so have changed the personalisation screen on the desktop version to make it an even bigger waste of screen space.
Interesting! Other provider names can be used at the moment.
Perhaps people have been creating social pies pretending to be Vanguard?
If you want Vanguard in a pie’s name, I guess you need to misspell it, or use a special character / emoji.
Perhaps Van Guard will work? 
I guess this might be something imposed by Vanguard as a condition of supplying the model portfolios. They won’t want their name on user generated pies.
