As late as 2020 I encountered a European shop that couldn't handle my Swedish address that had an å in it.

That is, it accepted the address on the website, but then it got screwed in the delivery.

I'm still in awe.

Sounds 'normal' if the website was built in a recent stack in recent years.

The shipping backend might run on a mainframe, almost if not fully unchanged from 40-50 years ago and blissfully unaware of anything but the mainframe quivalent of your standard ASCII.

You can see large stores run all their inventory and such on mainframes. If you ever look over someone's shoulder. My insurance also does but it looks like they don't because it has a nice standard Windows look on the 'inside' of the window. Looked at the title bar and yep, it's just a 3270 terminal emulator that renders fields as nice standard windows input fields that follow whatever theme your computer is set to instead of your telltale black background "DOS" look.

you'd be even more impressed to find out how often polish characters (ąęłćśżźńó) get totally screwed in... poland itself

UPS sent me a parcel and replaced ä with ae

That’s a valid and common replacement for German umlauts

That was not a German umlaut

As I remember it, the RSS readers under test did not correctly handle encodings, blissfully ignorant of the difference between UTF-8 and Latin-1. Many had processing pipelines that did not preserve encoding.