Android : How does Android handle unknown XML tags?

According to Android Lint, some XML attributes cause crashes on older devices. For example, Attribute 'paddingStart' referenced here can result in a crash on some specific devices older than API 17

Does this mean I need separate XML files to support unknown tags (e.g. the same layout with the paddingStart attribute added in a layout-v17 resource directory)?

I don't like the idea of having an extra, nearly identical file, as this is prone to errors when I update my code. Will some devices actually crash? I would've thought unknown tags would just be ignored.