We noticed that the examples that use tiger2016 in the README, as here https://github.com/censusreporter/census-api/blob/7529031043269585eb0ad0d8f34ea62082588c61/API.md#geography
Are now producing an "Unknown TIGER release" error:

That's here: https://api.censusreporter.org/1.0/geo/tiger2016/04000US55
But this does work:
https://api.censusreporter.org/1.0/geo/tiger2017/04000US55

I see these changes came in this commit late last year, aaef5a5.
Maybe just a matter of updating the docs then.
Would we expect the endpoints to change again in the future?