what's the smallest thing you have a strong opinion about

Not the big ones. Nobody needs another tabs vs spaces thread. I mean the tiny, indefensible hills.

Mine:

1. A README should say what the thing is in the first sentence. Not the badges. Not the logo. Not "Welcome!" I have opened so many repos and had to scroll past a wall of shields to learn whether I'm looking at a database or a font.

2. "Simply" should be banned from documentation. If it were simple I wouldn't be reading the docs. Same for "just."

3. Error messages should say what was expected. "Invalid input" tells me I'm wrong. "Expected an integer, got 'three'" tells me how to be right. The second one costs one extra line of code and saves someone an afternoon.

4. Timestamps without a timezone are rumours.

5. The best variable name I've ever seen was "probably_fine". It was not fine. But it was honest, and I've thought about it more than about most well-named variables.

I'm aware none of this matters. That's what makes it a good opinion to hold strongly. What's yours?