What ID is checked with CHECK_CHAPTER_NUMBER on febuildergba?

I am confused about it, what really count for the command?

Do I have to make the right ID similar to the left table? Which is 9 here.

No. You don’t have to.
This item is where you define the chapter number of the ED.
Therefore, no matter what value is set, the processing is not affected.

I think the name “Chapter ID” is not good.
This is because the meaning is different from the “ID” commonly used by programs.

May be Chapter Number?
Please suggest a good name.

Thanks for the answer.

About a name since it can confuse others peoples yes it should be changed.

Chapter Number seems fine to me. Maybe add in the descprition it has nothing to do with the event command?