Really, this seems the weight of the horizontal stroke? why? strokeshortoverlaycomb
That is a combining accent across a single stem. In Latin, this can be used for the crossbar in
strokeshortoverlaycomb.case for the uppercase letters
Eth (which, by default, serves as a component for
For uppercase Hbar, it will be a
strokelongoverlaycomb.case, because it crosses two stems.