Ask HN: What do your programming notebook entries look like?

There have been many posts of what medium to take programming notes in, but I am more curious about what people's notes actually look like. What things do you find useful to keep? How do you organize the material inside each entry? Any actual examples would be amazing!

I've come to realize the benefits of notetaking, and I have started to do it myself. But right now I have entries by day in which I keep notes from any project in, and it ends up looking like an unorganized brain dump and something not really useful in the future.

Thanks for the info!