Rails uses plural everywhere, this is not a good design. For 'show' action, let's use single form, and for list let's use plural form. 

/user/weli@redhat.com
/users/
/package/abc -> return package abc (if there are multiple 'abc's with different 'os'es, return the first one get from database).
/packages/abc ->  return all the packages with name 'abc'