hey @cooltrickboi ,

Steemit supports so called Markdown (name is a word play on html's Hyper Text MARKUP Language). It's a formatting language that uses it's own syntax and usually a subset of HTML code.

Markdown rules: https://guides.github.com/features/mastering-markdown/

This post sumarizes, what should be possible in Steemit markdown https://steemit.com/basic/@magnebit/some-basic-html-formatting-in-steem (meaning what is doable trough HTML syntax or markdown syntax).

The trick with Markdown implementation is that most pages have their own flavor when it comes to raw HTML support (not to mention rendering). Best starting point however, is official documentation of Markdown you can fine here: https://daringfireball.net/projects/markdown/syntax#html

For any markup that is not covered by Markdown’s syntax, you simply use HTML itself. There’s no need to preface it or delimit it to indicate that you’re switching from Markdown to HTML; you just use the tags.

The only restrictions are that block-level HTML elements — e.g.<div>, <table>, <pre>, <p> etc. — must be separated from surrounding content by blank lines, and the start and end tags of the block should not be indented with tabs or spaces. Markdown is smart enough not to add extra (unwanted) <p> tags around HTML block-level tags.

However, I can tell right away, that you won't be able to run PHP or inline scripts (such as javascript). The only way to insert dynamic content might be trough iframe.

Hope that helps a bit.