RapidWeaver uses the theme.plist file to gather all the information it needs about the theme.
The Theme.plist file is a standard xml file, meaning, if you have the developer tools installed, you can use Apple’s Property List Editor to create and edit your themes plist.
You can also use a text editor such as TextWrangler or TextEdit that comes free with macOS.
These tags are displayed in alpabetical order. Large dictionarys such as RWStyleVariations and RWTextTool- Bar can be found in thier own categories.