The few lines of code.. can someone just walk me trough what it is I am looking at?

Code:
r3
k(69.0.0):hs(form.diamond)
k(87.0.0):hs(form.stack)
r3 = Region 3 (This I get)

k?
69.0.0 ?

:hs ?

Any explanations or documentation on this?


Thanks!