Minecraft wiki entry for Development_versions, associated text: MC-140950 – Armor on player or entities is misaligned.
MC-140969 – Villager/zombie villager clothes remain visible when villager is invisible.
MC-140974 – Z-fighting on invisible villager's clothes and end of sleeve, as well as bottom of main body and legs
MC-140991 – Breaking an observer with a bell attached does not break the bell.
MC-141101 – Bell turns into double_wall state when updated with a noteblock.
MC-142114 – Joining the world outside of the spawn chunks results in client side desync.