Depending on the type/manufacturer, you have two options for labeling your push buttons. Labels can be etched on the push button, or sold as plain stainless steel covers with text labels etched into the panel above the switch. Again, this choice is up to personal preference and the scope of your project.
That said, etched push buttons do have some clear advantages over plain stainless steel. Namely, an etched push button is much more interchangeable — and a label that’s up on the panel is a lot more permanent.
With an etched push button, you can easily change the insert. Unless you’re replacing the entire dash panel, you can’t change out the text above a stainless steel switch. Essentially, the non-etched option is just for people who know they need one replacement for a specific button on a dash that is already labeled on the panel.