Strange symbol using custom fact type

I am learning how to create new fact types - specifically one for Travel.
In my first attempts the fact type appeared as in the attached image.
The fact type didn’t work - seemed to default to something about being a witness.
Anyone know the significance of the small green square with the diagonal double arrow head?
In the meantime I think I have the fact working but am curious about the green square.
Symbol mystery

That symbol means that the fact was shared with that person. Roles (i.e. witness), are only used in a shared fact. In the sidebar, when the fact is highlighted, you can see where the fact has been shared by clicking in “shared line” in Fact items

1 Like

Thank you Alaine.
Your help is much appreciated.