Does html specification state what happens when both bottom and margin-bottom are specified?

Question

To me specifying both bottom and margin-bottom seems like a contradiction. Because both are means to specify indent between the element and surrounding elements/containers. That is, bottom should be measured from the border, otherwise it's indent measured from indent. Does anyone know what the specification has to say?

Answer 1

bottom property "specifies how far a box's bottom margin edge is offset above the bottom of the box's containing block"¹. And

The margin edge surrounds the box margin. If the margin has 0 width, the margin edge is the same as the border edge. The four margin edges define the box's margin box."²

So yes, specification says that bottom is measured from margin edge.