The wiki text format is a simple plain texts format. It is very easy to edit using any text editor and it also works very well with version control systems.
The wiki text format uses two pipe characters (||) to separate between command, first, and second parameter.

A simple test script might look like this

open-url        || https://www.wetator.org/testform

assert-title    || WETATOR / Test Form
assert-content  || The form below is only for testing purpose

set             || Project name    ||  My Fancy Web App Under Test
select          || JAVA
select          || amazing
select          || visionary
set             || Wetator makes   ||  testing fun
set             || my resume       ||  resume.txt

click-on        || Submit My Truth
assert-content  || Thank you for submitting your truth about WETATOR

As you can see the format is really simple. Of course there is no need to place all the separators ('||') in the same column but doing so will result in more readable files.

Comments

If you like to add comments to your file just start the line with '#' or '//'

open-url        || https://www.wetator.org/testform

# check form content
assert-title    || WETATOR / Test Form
assert-content  || The form below is only for testing purpose

# fill the form
set             || Project name    ||  My Fancy Web App Under Test
....

Multiline

Especially for the describe command you need a way to provide multiline content; this can be done by simply ending a line using the \ as continuation character.

describe        || My first simple testcase for [WETATOR](https://www.wetator.org) \
This case consists of some tricky steps \
* open the url \
* fill the form and \
* finally check the result

# time to start
open-url        || https://www.wetator.org/testform
....

I18n

Wetator always assumes UTF-8 encoding of your wiki text file. If your editor uses this encoding also, you have no need to do anything special when working with unicode characters. Additionally you can use the Java/C way of unicode encoding (\uxxxx) to place special characters in your file.
This sample selects the 'µl' from a list of units.

....
select          || unit > \u00B5l
....