Sheet pan/baking tray convention outside the US? In this video, a Frenchman visits New York and buys a half sheet pan, which he appears unfamiliar with (both the term and the device itself) despite being an experienced cook. So I'm wondering: is there not a sheet pan convention outside the US? I'd just assumed that the full/half/quarter sheet system was universal. Ditto for the sheet pan itself, since it's cheap and indestructible. Are those only used in the US?

(I did find this history of the standard sheet pan, which discusses patent filings and brand names in the US in the early 20th century, but that thread doesn't discuss whether it's unique to the US.)
I'm not aware of any standard size baking trays in Europe. Here in Germany your baking tray comes with your oven. As several manufactures produce basically the same product some trays may be used interchangeably, but there is no guarantee that they really fit.

You can purchase universal folding trays that can adjust to the different ovens but they come with their own issues.