Hacker News Reader

I can't help but interpret that as a clue as to which internal groups hold power over there.

Huh?

Lowercase "in" is a major part of their branding. Forcing usage of lowercase "in" in this scenario supports the branding even if it doesn't make sense from an engineering standpoint.

That's why engineering should silently add a toLowerCase and just generate qr codes with lower case as well.

They can redirect from the upper to the lower case URL so that it still looks the way they want.

It might not be intentional that it doesn’t work with uppercase, but they just made it lower case and by default it’s case sensitive on whatever software stack they use to host.

I would not link directly to LinkedIn. They have changed the optimal url many times.

According to the article / is not in basic alphanumeric alphabet anyway?

The article has an off-by-one error. There are 45 characters in the basic alphanumeric alphabet, and / is the missing one.