The most recent versions of the datasheets for the TinyAVR product line are combined versions across different pin counts. This page collects links to the most recent versions of the datasheets as of July 2020, as well as the "silicon errata" sheets, which describe bugs in different versions of the hardware. There is also a page summarizing the errata including tables listing what issues apply to which parts on the silicon errata page.
ATtiny212/214/412/414/416 || ATtiny212/214/412/414/416 Silicon Errata
ATtiny212/214/412/414 Automotive || ATtiny212/214/412/414 Automotive Silicon Errata
ATtiny417/814/816/817 || ATtiny417/814/816/817 Silicon Errata
ATtiny416/417/814/816/817 Automotive || ATtiny416/417/814/816/817 Automotive Silicon Errata
ATtiny1614/1616/1617 || ATtiny1614/1616/1617 Silicon Errata
ATtiny1614/1616/1617 Automotive || ATtiny1614/1616/1617 Automotive Silicon Errata
ATtiny3216/3217 || ATtiny3216/3217 Silicon Errata
ATtiny3216/3217 Automotive || ATtiny3216/3217 Automotive Silicon Errata
ATtiny202/402 || ATtiny202/402 Silicon Errata
ATtiny204/404 || ATtiny204/404 Silicon Errata
ATtiny406 || ATtiny406 Silicon Errata
ATtiny202/204/402/404/406 Automotive || ATtiny202/204/402/404/406 Automotive Silicon Errata
ATtiny804/1604 || ATtiny804/1604 Silicon Errata