Lines starting with '* ' make an element of a dotted list:

List of languages:

Rust

Common Lisp

Scheme

Python

** two or more of * do not work

Lines starting with '# ' (or '## ', '### ') construct a header:

L1 header

L2 header

L3 header

oops, too many #s

Lines starting with '=> ' followed by <URI> and optionally [name] are for links to other web resources:

Some links I find interesting

Lines starting with '> ' are for quoting, I suppose:

> This is some boldy phrase.

Lines starting with ``` toggle preformatted mode On/Off:

Aaand back to normal

That's is it, or have I forgetten something?

Gemtext cheatsheet