How to use .abs- (from abstract) from UI library LESS?

Question

Magento Documentation for UI Library has said to use "Extend class names should have prefix .abs- (from abstract)"

There is no other explanation for the usage in the documentation

How should we use it in LESS?

Answer 1

It's just a naming convention so it's easier to know which classes are designed to be extended, they are to be used like this:

.your-selector {
    &:extend(.abs-reset-list all)
}

Where .abs-reset-list is the selector you want to extend.

This is core LESS functionality and isn't really related to Magento other than they prefix their class names with abs-