This can include stuff like:
- Media references, like "I'm on a boat"
- Regional slang, like naff
- Internet memes, like Rick Rolling
- Subcultural references, like diesel punk
It feels like a really important thing to do, not just for our international readers who are like, "No seriously, wtf is Reading Rainbow?" but even for our domestic readers who just A) don't like feeling like they're on the outside of an in-joke or B) love learning about new things. The goal in each of these cases is to ensure that as many readers as possible can relate to the material, and that readers who are curious about the cultural reference can disappear down a little internet rabbit hole and go learn about something new.
I totally get that inside jokes and winky-winky cultural references that only certain people get can be REALLY fun, but I think encouraging readers to get up to their elbows in some new cultural contexts is TWICE as much fun.