OpenBSD's pledge(2) was first talked about publicly as tame(2), and was presented in at FSec 2015, it was renamed pledge(2) as mentioned on the OpenBSD 5.9 page.
https://www.openbsd.org/papers/tame-fsec2015/
https://www.openbsd.org/papers/tame-fsec2015/
I'll concede that's less likely and I'm probably just wrong and misremembering though.