$fr-rolesXPath variable can be used in formulas controlling whether a field or section is visible or readonly.
$fr-rolescontains the list (as an XPath sequence) of roles of the current user, if any. Each role is represented as a string.
false(). If the control is visible, you can make it readonly to current user by defining a readonly expression that returns
true()if at least one of the roles is
admin, even if there are other roles available.