What are the different ways to customize content inside a post (custom attributes and such)

[RGJ (Richard - Communiteq)]

@SaraDev

and I believe it would look similar to something like this: Discourse HTML Whitelist

That code does not work any more. It’s better to remove that from your post.

The answer is in the topic linked to, as @canapin already found out.

Please note that the whiteList() function is deprecated and it is called allowList() nowadays.