HTML

[ella]

Here's HTML that Goodreads allows.

Random HTML

Hyperlinks
<a href="link">your text here</a>

Bolding
<b> your text here </b>
or <strong>your text here</strong>

Italics
<i> your text here </i>
or <em>your text here </em>

Underlining
<u> your text here </u>

Strike
<s> your text here </s>

(view spoiler)[Spoiler tag (hide spoiler)]
<spoiler> your text here </spoiler>

 Exact spacing

<pre> your text here </pre>

Blockquote

<blockquote> your text here </blockquote>

Paragraph

<p> your text here </p>

Image
<img src="link of image"/>
If you need to resize it:
<img src="link of image" width="number between 0-400" height="number between 0-400"/>

[ella]

Other

Arrow ↳
&#x21b3;
Arrow →
&#x2192;

Heart ♥
&hearts;

  Double space or whatever you call it
&nbsp;

Bullet point •
&#x2022;

Those are only a few, you can view many symbols here, at fsymbols. Just press HTML 5 on it, and you'll get the little code.