The engine comes pre-loaded with a lot of useful tags. Generally, a tag is just a sort of special command inside of [square brackets]. If you actually wanted to type square brackets, type \[ to make them appear. Below is a quick summary of available tags:

Text effects:

You can also apply visual effects to the text using the tags [wave] and [shake] along with a [/fx] tag. Text will begin animating in a sine wave pattern or wiggling randomly at the spot where the tag begins, and will end the effect when the [/fx] tag is reached. These effects stack, so you can type [wave]This is a [shake]test[/fx][/fx] and you'll see the first 3 words wave, while the final word waves and shakes.