old_contents: // common constants, shared between multiple pieces of code (and likely client and server)
  function d(name, value) {
    Object.defineProperty(module.exports, name,
        { value: value
        , enumerable: true
        })
  }
  
  d('USERNAME_PATTERN', /^[A-Za-z0-9`~!$^&*()[\]\-_+=<>]+$/)
  d('USERNAME_MINLENGTH', 3)
  d('USERNAME_MAXLENGTH', 24) // TODO(tec27): rooted in BW's limitations, maybe we should rethink it
  
  d('PASSWORD_MINLENGTH', 6)
  
new_contents: // common constants, shared between multiple pieces of code (and likely client and server)
  function d(name, value) {
    Object.defineProperty(module.exports, name,
        { value: value
        , enumerable: true
        })
  }
  
  d('USERNAME_PATTERN', /^[A-Za-z0-9`~!$^&*()[\]\-_+=.{}]+$/)
  d('USERNAME_MINLENGTH', 3)
  d('USERNAME_MAXLENGTH', 16)
  
  d('PASSWORD_MINLENGTH', 6)
  
subject: Update username format limitations.