Ruby - Naming Convention - letter case for acronyms in class/module names?

I need to create a class that represent "SVN" inside a module called "SCM". But I don't know what is the convention when dealing with acronyms in Ruby, and could not find anything relevant in Google, except "Camel case is preferred".

Should I call it SCM::SVN or Scm::Svn? Is there a convention for this?