Ask HN: Are the documentation standards?

I'm writing documentation (in markdown) for a project I'm working with and was curious if there are standards in terms of format/styling.

For example, if I am referencing a file, do I italicize the file name? Do I put it in an inline code block? I would think referencing a variable would go in an online code block and a block of code with use a "paragraph" code block. Then there's this like IP(normal text? Italics?) and a GUI button or menu item text (italicized?).

When I started thinking about it there's various conventions that made sense to me which made me wonder if there's a standard format/styling for this.