They need to somehow indicate that they want to communicate with me, I won't chat with them if I don't need to

Only if he/she says it first.

🥀 🐒 top of the mornin governa (being open to conversation takes practice) & at the end of the day saying goodbye is truly the toughest of things. I still think of this 1 person I met (lol he asked my cousin about me after) 😭 life is a cruel mistress.

I wouldn’t say hello, but I do smile or say morning or whatever. Sometimes they speak first, listen it’s weird in certain parts of the uk, you just do these things and nobody knows why.
You never NEVER do that in London though, just walk around and pretend nobody around you exists.

...there would have to be a reason. I'm a sucker for talking to strangers who talk to me first though.

That's awkward.

1. At work as people approach me. I'd rather say, "what's up?" but that illegal
2. When a stranger says "hello" to me
3. When I decide to live on the wild side and answer calls from unknown numbers
   
4. When a child is staring at me for an extended amount of time at close range, and I assume they want me to acknowledge them.
5. When I need someone who works somewhere to do a thing for me.
6. Any time the stranger is a squirrel that I can see
7. When I accidentally make eye contact with someone while waiting in a line

Since I grew up on the countryside: any time you pass by one.

When we stumble across each other? Or when they lose something and I pick it up for them to hand it over? many other similar occasions?

Like Scott, every time I’m out. In Scotland. If you did it in London people would think you’re after something.

Either out of sheer politeness, as in entering a waiting room at the doctor’s office or beginning an interaction with the cashier. Or when I have very good reason to demand someone’s attention, if they lost something or don’t realise they are about to do something stupid.

The thought of going to a stranger, say hello and start a conversation gives me anxiety. Although I learned that this is completely customary behaviour in other regions in Europe.