Mvt Types 107 & 108 in ECC6.0 Release

What the significance of new Mvt Types 107 & 108?

107 is for Valuated GR Blocked stock. What scenario this Mvt Type is useful?

As accounting takes place during this Mvt, shall we post Invoice after this Mvt w/o doing 109?

Please clarify me any body

Thanks in advance.

Kanth