> is that a matched pair of zeners?
Define "matched".
Some days I'd call 12V and 15V a mis-match; other times that's close enough for Rock&Roll.
If you are doing Government Work, better read the test specs in your government contract.
Sorry, I do not recall the context in which I wrote the above.
It also appears to be for forward diodes, not Zeners. The idea is the same. Off hand I am not thinking of any great urge to close-match Zeners over a wide range of currents.