Scholia are notes or comments on a text, usually written by someone else.
Scholia can help people understand a text better, but they can also be annoying if there are too many of them.
Examples:
The book had many scholia in the margins.
She wrote some scholia in her notebook while reading.
The teacher's scholia helped me understand the story.
I don't like it when there are too many scholia in my books.
The ancient text had so many scholia that it was hard to read.
The scholia in the book were very helpful.