Some of the posts I’ve read contain code snippets which are not visible by default, requiring a “Click” to show up. How can one obtain such a feature? I checked FAQ but it is about completely different topics (“be polite etc.”). There are (unless I miss something obvious) no help page covering technical topics of editing the posts.
It is called a “Details disclosure element”.
You can type it directly in HTML:
<details> <summary>Details</summary> Something small enough to escape casual notice. </details>
DetailsSomething small enough to escape casual notice.
You can also find it under the “gear” tool tab as “Hide Details”.
The syntax is slightly different:
[details="Summary"] This text will be hidden [/details]
This text will be hidden