Control names in descendants – PB Docs 2019

PowerBuilder uses this syntax to show names of inherited
controls:

For example, if you select the Open button in w_customer, which
is inherited from w_ancestor, its name displays on the General page in
the properties view as w_ancestor::cb_open.

Names of controls must be unique in an inheritance hierarchy.
For example, you cannot have a CommandButton named cb_close defined in
an ancestor and a different CommandButton named cb_close defined in a
child. You should develop a naming convention for controls in windows
that you plan to use as ancestors.