Name of "bar" on left side of subform

[X]

I would like to not see the "bar" on the left side of the
subform and would like to have a way to delete it or make
it not visible. What is that "bar" called? It's not a
taskbar nor a scrollbar,etc.

 

[Van T. Dinh]

I think you meant the Record Selector. It is a Property of the Form (you
used as the Subform).

Open the (sub) Form in DesignView, open its Properties window and you should
see the "Record Selector" Property in the "Format" tab.