Copying&pasting from the javadoc:
An EnumConverter allowing stories prose to be more natural. Before performing the actual conversion, it transforms values to upper-case, with any non-alphanumeric character replaced by an underscore ('_').
Example: assuming we have defined the step "Given I am on the $page" which is mapped to the method iAmOnPage(PageEnum page), we can then write in a scenario:
Given I am on the login page
Given I am on the LOGIN_PAGE
Warning. This requires enum constants to follow the standard conventions for constant names, i.e. all uppercase letters, with words separated by underscores.