The note in [Section 2.1. Containing Blocks of Positioned Boxes](https://drafts.csswg.org/css-position-3/#def-cb) states: > Properties that can cause a box to establish a fixed positioning containing block include `transform`, `will-change`, `contain`… The ellipsis (`…`) at the end suggests this is not an exhaustive list. Please list all relevant specified properties that cause an element to establish a containing block for fixed-position descendants.