This is an exact duplicate of an bug I just reported over on WhatWG's spec; details at whatwg/html#1521.

The non-normative index of elements currently has flow* under "Categories" and "Parents". Unless I'm missing something, both of these have been incorrect since @domenic removed the scoped attribute in #1226. I guess that he missed this because he implemented the removal by reverting 29cf39d and related commits, but the elements index was not added until 3 years after scoped was added (778068c) and so just looking at the commits that added scoped could never reveal this bug.

The current draft of the W3C's HTML 5.2 spec is similarly affected, despite them having removed scoped independently.

In the next few minutes I'm going to push up a PR to fix this on this repo, open an issue about this on the W3C repo linking to this one, and open a duplicate PR on their repo.

_{Aside: the duplication of labour y'all have going on between the two specs is a tragic waste of good people's time and makes me sad.}

Will push a PR to fix it as soon as I've read the contributing guidelines.