I believe its used to signify that tritium is used for the lume before Super luminova was introduced. It might be there to serve as a warning as tritium is radioactive not strong enough to make it through the watch and from what I have read the bata radiation cant make it through the skin. Still I wouldn't want to touch it.Nice PAM! That is the one i want!
On the first TAG, why is the "Swiss Made" surrounded by T-Swiss Made-T? ...always wondered that