"Accordion" class unrecognized in local Bootstrap 5

Question

I am following the Bootstrap 5 docs to create a vertically collapsing Accordion, as detailed at https://getbootstrap.com/docs/5.0/components/accordion/

However, despite having installed this library with libman, the main class "Accordion" throws an editor warning in Visual Studio 2019: "Unknown CSS class: 'accordion'".

This is the only class in BS5 with which I'm seeing this issue.

If you know why this might be, I'd appreciate the help.

Answer 1

Apparently that is because it is not actually used as a CSS class by Bootstrap. If you search the CDN source code you will not find ".accordion " (w/ space after) but there will be 31 instances of .accordion-* for the child-element styles.
I also searched the bootstrap.js and "accordion" does not occur anywhere in the file. You can also inspect the example on the docs page and see no rules for the class, and removing the class has no affect. Therefore, it would appear that its use is purely just for convenience if you want override something.