Casting number question

I've heard many different responses to the dash number. One being it was a revision so therefore up a dash number, another was repairs (shifted...)Having made molds myself for the automotive industry, in the past.

The molds were numbered by cavity numbers, as they are typically more then one mold. This was done for traceability, incase they're would be an issue with a specific mold then it could be addressed.

That's my take on this.