Directives begin with a "#" followed by name of the directive - #set, #get, #foreach etc.
You can pass different parameters to all of them. Some Directives like #set, #sub ,#var and #dump don't have body. Other - like #foreach, #if, have body.
You can find all possible Directives in Skin above the text field with code.
If you click on Directives it will show a list with all available directives.
When you hover mouse over the Directive, you can see its syntax.
By clicking on Directive from menu, it will appear in code editor. Below is an example – first line is when you click on some directive – in our case #set. This one is for setting a variable. You have to replace the <Variable> and <Value> placeholders with a real one.
For more information about Velocity Directives visit the official website:
https://people.apache.org/~henning/velocity/html/ch05.html