https://drafts.csswg.org/css2/#collapsing-margins

bottom margin of a last in-flow child and bottom margin of its parent if the parent has auto computed height

Note the above rules imply that:

• The bottom margin of an in-flow block box with a height of auto and a min-height of zero collapses with its last in-flow block-level child’s bottom margin if the box has no bottom padding and no bottom border and the child’s bottom margin does not collapse with a top margin that has clearance.

The note mentions a requirement for min-height: 0, where does this come from? The normative text only mentions min-height for a different case.

Testcase: https://software.hixie.ch/utilities/js/live-dom-viewer/saved/11745

• Gecko and Blink collapse as long as min-height doesn't increase the height.
• WebKit collapses regardless of min-height.

What about max-height? https://software.hixie.ch/utilities/js/live-dom-viewer/saved/11746

• Gecko and Blink collapse as long as max-height doesn't decrease the height.
• WebKit collapses regardless of max-height.

Worth noting that there is also this other case:

top and bottom margins of a box that does not establish a new block formatting context and that has zero computed min-height, zero or auto computed height, and no in-flow children

Testcase: https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=11751

Should the spec change to align with some browser? At least remove the spurious min-height: 0 from the note, or enforce it in the normative text.