HTML in Markdown

<div style="text-align: center">A centred paragraph.</div>

A centred paragraph.

Collapsible sections

<details>
<summary>A collapsible section</summary>
 
The content appears when unfolded. There has to be a blank line between `<summary>` and the text,
otherwise the Markdown inside it is not processed.
 
</details>

A collapsible section

The content appears when unfolded. There has to be a blank line between <summary> and the text, otherwise the Markdown inside it is not processed.

When HTML, when a callout

For anything collapsible the foldable callout is the better choice: it is designed, it has a focus ring and it works the same way in Obsidian. HTML pays off for things Markdown does not know at all — a table with merged cells, for instance.

What Markdown cannot do here

Definition lists (term / : explanation) are known to neither Obsidian nor Quartz — measured: the colon line stays there as text. Anyone needing them writes HTML:

<dl>
  <dt>Term</dt>
  <dd>The explanation for it</dd>
</dl>

Term

The explanation for it

For most cases a two-column table does the job — and it reads better on a smartphone.

HTML is not sanitised

What stands here lands on the page unchanged. With content from a foreign source that is a risk.