What are DPBP#'s ?

[LegacyEeveeVGC]

Ok, I was looking over my cards when something new caught my eye on the Call for Family EEVEE in
Majest Dawn. It has some number down at the left corner (DPBP#157) , so I went to look at the other EEVEE from the ste and it does not have any number at all.
POrygon-Z from GE also has a number, yet other cards don't.
I was wondering what this is for or is.

 

[PokePop]

It's an internal code that Pokemon uses.
They have not revealed any details regarding it's significance.

It has no significance to play.