I have attempted to name five Parrots of differing color separate names, (after having previously named three Cats of differing color as well), after which I Saved and Quit to back up my Save Data for my (Hardcore) World, especially because this is a Pre-release version of 1.12. After returning (all I did was copy the current Save data into another Folder, without modifying the original in any other way), I noticed that the Name Tags that I used for each Parrot had been returned to my Inventory, while the Name Tags for the Cats were still attached to the Cats. I tried renaming them, Saving & Quitting, and rejoining the world several times, but each time the Name Tags were returned to me. Later, after experimenting some more, I found out that a named Parrot also loses its name after riding on the Player's shoulders. Again, the Name Tag was returned after Saving & Quitting and rejoining the world.