Michael J. Hall, Ph.D.

Markdown

Markdown Syntax Reference

Apr 4, 2025 markdown references

Overview

This document is a collection of helpful Markdown syntax I’ve gathered for writing Markdown documents. It’s intended to provide useful tips and tricks, and will continue to evolve over time. It will serve as a quick reference for finding Markdown syntax.

Useful Links

Markdown Guide – An open-source reference guide that explains how to use Markdown.
W3Schools CSS Tutorial – A tutorial that teaches CSS from basic to advanced concepts.
W3Schools HTML Tutorial – A tutorial to learn HTML fundamentals and beyond.

Quick Reference

Horizontal Spaces

Space Type	HTML	Rendered Example
No space		ABC
Regular space	(regular space)	A B
Non-breaking space	` `	A B
Three non-breaking spaces	`   `	A B
En space	`&ensp;`	A B
Em space	`&emsp;`	A B
Hair space	`&hairsp;`	A B
Thin space	` `	A B
Medium mathematical space	` `	A B
Four-Per-Em space	` `	A B
Six-Per-Em space	` `	A B
Figure space	` `	1 2
Punctuation space	` `	A B
Narrow no-break space	` `	A B
Zero width space	`&ZeroWidthSpace;`	AB
CSS margin space	`<span style="margin-left: 50px;"></span>`	AB
CSS width space	`<span style="display: inline-block; width: 2em;"/></span>`	AB

Note, using <span> to create space makes the space visible, but it doesn’t insert actual space characters.

Dashes

Dash Type	Markdown	HTML	Rendered Output
Hyphen	`-`		-
En dash	`–`	`–`	–
Em dash	`—`	`—`	—
Double hyphen	`--`		–
Triple hyphen	`---`		—

Depending on the engine, the double or triple hyphen may render as an En dash or Em dash.