What is the correct HTML semantics for lists of content that has explanations such as changelog entries? For instance, have a look at the following: A, B. Both pages use definition term (dt) elements to subhead an item/feature, with list items in a ul placed beneath:
<dl><dt>New item</dt></dl>
<ul><li>Does some thing</li></ul>
This is incorrect semantics (see #3275054), but what should it be instead?
Alternatives such as h4 would be complete overkill navigation-wise.
I’m not sure what you mean by ‘correct semantics’; if you’re using HTML rather than XML you have to fit your data to one of the available structures. My inclination would be to use a H3 (or some other heading level) for the major sections, and a DL for the minor sections, with DTs as the “headers” and a UL inside the DD for the specific items. Using a section of the Terraria wiki that you pointed to...
<h3>ARMOR</h3>
<dl>
<dt>Ninja Armor</dt>
<dd>
<ul>
<li>Instead of throwing bonuses, each piece now gives a global 3% damage and 3% critical chance</li>
<li>New Set bonus: 20% movement speed</li>
</ul>
</dd>
</dl>
Which would present (modulo CSS) as