A <ul> is a list of things whose order makes no difference to its meaning. Rearranging a <ul> would change the presentation, not the information. Rearranging an <ol> would change both.
<ul> Players
<li> Alice
<li> Bob
<li> Carol
</ul>
<ol> Leaderboard
<li> Bob
<li> Alice
<li> Carol
</ol>Too late to edit now, but I should mention putting titles in a list like that isn't valid. It's just to shorten the example.
Exactly. “Unordered” implies “reordering doesn’t change meaning.” And yet that’s already implicit in the bullets (vs numbers).
So is it a decoration hint? Or is it actually semantic? And what system is interpreting the semantics rather than the visual presentation?