I know that spoiler tags don't support all the same kind of Markdown that block quotes do, specifically lists and paragraph breaks. So, I was trying to use HTML to produce the effect that I wanted, which was a bulleted list inside a spoiler.
The effect I got looked a bit strange -- there was excess space at the top and bottom of the spoiler block. so, I examined the HTML it was producing and noticed that it was creating what I'll call "dodgy" HTML. In particular, it's producing extra paragraph tags before and after the embedded HTML. Even more strange, if there's additional text after the HTML, it's not being wrapped in a
<p> tag, but there's an empty
<p> tag anyway.
It's probably easier to show. If I include this markup in my post:
>! <ul><li>This list is weird</li></ul>
then the HTML includes empty paragraphs before/after the HTML, which means unwanted white space inside the spoiler:
<blockquote class="spoiler"> <p> </p><ul><li>This list is weird</li></ul><p></p> </blockquote>
If I actually include header/footer text, it gets even stranger:
>! Header <ul><li>List Item</li></ul> Footer
the resulting HTML that I get is:
<blockquote class="spoiler"> <p> Header </p><ul><li>List Item</li></ul> Footer<p></p> </blockquote>
In particular, note the placement of the "Footer" text, which seems to be confusing Chrome: