A widget attribute can be named three different ways: by its command-line option, by its resource name, and by its resource class. The command-line option is the format you use in Tcl scripts. This form is always all lowercase and prefixed with a hyphen (e.g., -offvalue). The resource name for the attribute has no leading hyphen, and it has uppercase letters at internal word boundaries (e.g., offValue). The resource class begins with an uppercase letter and has uppercase letters at internal word boundaries. (e.g., OffValue).
The tables in this book list widget attributes by their resource name.