Aliases are commands you can write to send a complex phrase by typing a single word.
To create a new alias:
Click on the "+" button. You'll see a new untitled entry in the list of aliases.
Double-click on the line of the new entry. The area will turn into a text entry field, and you can type a new name for the alias.
Enter the shorthand command you want to use in the Command text field.
In the Script text area, type the text you want Cantrip to send when you enter the alias. Note that the text will be sent as a complete command to the MU*, instead of being put in the Input Area.
To delete an alias, select it in the list, and click the "-" button. To turn it off temporarily, uncheck the checkbox for that alias.