IIS : regexes for name properties are more restrictive than iis itself

^[a-zA-Z0-9\-\_'\s]+$ 

PS C:\Users\Administrator> New-WebSite -Name "Test.Site" -Port 80 -HostHeader "Test" -PhysicalPath "c:\"

Name             ID   State      Physical Path                  Bindings

----             --   -----      -------------                  --------

Test.Site        2310 Started    c:\                            http *:80:Test

  newparam(:name, :namevar => true) do

    desc "The Name of the IIS site. Used for uniqueness. Will set the target to this value if target is unset."

    validate do |value|

      if value.nil? or value.empty?

        raise ArgumentError, "A non-empty name must be specified."

      end

      fail("#{name} is not a valid web site name") unless value =~ /^[a-zA-Z0-9\-\_'\s]+$/

    end

  end

Error: Failed to apply catalog: Parameter name failed on Iis_site[test.site]: name is not a valid web site name at ...