tr/// (sometimes spelled y///

Hm, I have been using perl for something like 20 years and even though I have never (as far as I can remember) used tr at all I always knew it existed and what it does.

"tr" must be short for "translate", but today I learn there is even another version of it - you can trade "tr" for "y" - well who would have guessed.

As I am (a bit) interested in perl-arcana:

Does anyone know where this "y" comes from?

Is is a reference to another language who's users larry wanted to feel at home? Can anyone please enlighten me?

Many thanks!